Maybe. Maybe not. Lets see, suppose a CEO earned $1,000,000 in 1979 and pays $400,000 in taxes. The same CEO earned $50,000,000 in 1997 and pays $20,000,000 in taxes. Suppose everybody else stays the same. The CEO is paying a heck of a lot more of the percent of tax in 1997, BUT, it is because his share of the earnings has greatly increased. I will see if I can use your numbers and verify or rebut this possibility. Hardcopying as we speaketh. parsy.
The only way to "fix" this is to have "the rich" pay an effective rate > 50%.
(I'm certainly not saying that's fair. Is it fair for someone's income to double, while their % of the tax pie increases > 2X?)