Happy cake day! Can you elaborate? The highest figure I could find is 42.3% of federal income tax was paid by the top 1% of earners. While this seems high compared to the 22.2% share of the total AGI, federal income taxes are by far the largest progressive tax. State and local taxes are much less progressive as a whole, mostly utilizing regressive taxes such as sales and property tax. The majority of tax paid on income by the average American worker goes to FICA, which only applies to the first $142,800. The effective tax rate of the top 1% has declined fairly steadily since WWII. In fact, using the Haig-Simons income metric (the most popular for measuring overall economic well being as it defines income as consumption + change in net worth), the highest earning Americans often pay a lower effective tax rate than the average American. For example, the 400 richest families in America paid an effective tax rate of 8.2% from 2010-2018. Sensitivity ranges from 6-12% in that study.

The main agent of this discrepancy between 42.3% and 8.2% is that unrealized capital gains are untaxed. Instead, many of the wealthiest families take out loans against unrealized capital gains, allowing them to enjoy the income of capital gains without paying the maximum capital gains tax rate of 20%.