Tax day doesn’t sting much if you live at the gilded edge, according to new data on how the top one-hundredth of one percent and the top one-thousandth of a percent of all filers pay their income taxes. People who make tens of millions of dollars enjoyed falling income tax rates and ballooning wealth for a decade as middle-class taxpayers floundered.

The new Internal Revenue Service (IRS) data helps illustrate the logic behind Sen. Bernie Sanders’ (I-VT) call for radically reshaping the American income tax system to create pricey new brackets for extremely high earners. The numbers provide a deeper look inside the highest income echelon, breaking out data on income tax rates and total yearly earnings in previously unpublished detail. In the last year of the Bush tax cuts, there were well over a thousand people who reported more than $60 million in earnings but paid federal income tax rates far below 20 percent.

In late May, Sanders called for restoring top income tax rates as high as 90 percent. The graduated income tax system means that policymakers could create new tax brackets up at that level without raising taxes on everyone below whatever level of wealth they choose to target.

Sanders based his comments on generalized information about wealth inequality, but the new IRS data on income inequality bolster his argument. Currently, the highest income tax bracket and capital gains tax bracket each kick in at a little over $400,000 in annual income. But there are nearly 14,000 tax filers who earned more than $12 million in 2012 as members of the best-paid 0.01 percent of all taxpayers, according to the IRS, and about 1,360 who earned over $62 million that year. Their vast earnings were not taxed any more heavily – and indeed, they paid a lower overall income tax rate than their merely one-percent brethren.

It is the first time the IRS has ever broken out income tax data at the very top end of the earnings spectrum. Previous releases have shown the top 1 percent and the top 0.1 percent of filers, but the new data drill deeper. There were a little under 1,400 income tax returns filed in that very richest sliver of data in 2012, the agency reports, with an average income of roughly $161 million for the year.

The poorest filer to qualify for that group in 2012 made $62,068,187 in adjusted gross income (AGI). Like a tax wonk’s version of the “must be this high to ride” sign at a carnival, these threshold income levels for each grouping in the IRS data offer working definitions of the economic class each category depicts.

The income threshold that defined the top 50 percent of all tax returns offers a snapshot of life in the economic middle, and its decline over the decade is bad news for middle-class families. Other indicators of life in the middle over the same timeframe as the IRS data paint a dim picture. Wages were stagnant or even falling for these families, yet the cost of the core components of a middle class life jumped by thousands of dollars.

The inflation-adjusted IRS numbers confirm what other evidence has suggested: middle class families have seen their earning power decline significantly even as life in the fast lane has gotten richer and richer. One-percenter incomes were about one-sixth higher in 2012 than in 2003, after adjusting for inflation. The richest one-thousandth of a percent of tax filers made about 75 percent more than they had a decade prior. But as those extremely rich people got richer, the middle class got poorer. The income threshold for being in the top half of all tax returns fell by 8 percent over the decade, creating the 2012 disparity between .001-percenters who earned at least $62 million, one-percenters making $435,000 or more, and workers paying federal income taxes on earnings as low as $36,055.

Part of the reason the 2012 data show such a dramatic gap is that wealthy people had incentive to cash out investments to take advantage of the final year of the lower Bush-era tax rates on capital gains. But because capital gains taxes are still significantly below normal income taxes, and because there are still no tax brackets targeting people who routinely earn several million dollars in a single year, the general pattern shown in these numbers is not going anywhere until the tax code gets radically revised.

The federal-only, income-only tax data do not factor in the state taxes, sales taxes, and other contributions to the public weal made by the half of the country who earned so little that they owed no federal income tax. But the statistics on the federal income tax rate paid at various Adjusted Gross Income (AGI) levels illustrate how flat America’s primary tax collection tool has become after decades of chipping away at a system that was much more steeply progressive prior to the Kennedy presidency.

If your AGI was above $36,055 in 2012, you were in the top 50 percent of tax returns. You are part of the herd that paid nearly all of the income tax revenue collected for the year. The 68 million individual taxpayers represented in that group paid an average federal income tax rate of 14.33 percent – just over 3 percentage points lower than what you paid if you were in the top one-thousandth of one percent of all earners. That means a group of about 1,400 taxpayers who earned an average of $161 million in 2012 paid less than a fifth of that one-year fortune to the government in income taxes.

People who made more than $60 million kept more of that income in 2012 than those who made $13 million. The income tax code ends up being regressive at the very top — it takes a smaller piece of the very biggest pies — almost entirely because of capital gains taxes. Previous research by the Center for American Progress’ Harry Stein has found that 95 percent of the decline in income tax rates at the tippy-top of the economic spectrum can be explained by capital gains tax rate cuts.

The income tax system was only minimally regressive overall throughout this decade of IRS data, and at the very top it actually turned around and became regressive. These design flaws have helped to create the extreme wealth inequality that’s motivated Sanders to campaign against “a casino-type capitalism…where the people on top have lost any sense of responsibility for the rest of society,” as the Vermont socialist put it to CNBC in May.

Originally published by ThinkProgress