The effective tax rate calculation is wrong on page 1 of my return: 16.53%. If I divide my "Total Tax" by my AGI, I get 22.6%. By my Taxable Income, I get 25.3%. Why?

Even if I divide by my Total Income from line 7b of my return (which is obviously wrong but the largest number anywhere in my return), I get 20.4%. (The numerator for all of the above is line 16, Total Tax.)