-27.74% is the change from 721 to 521
Calculation steps:
[( 521 - 721 ) ÷ 721] x 100 = -27.74%
Formula
Percentage change = [(521 - 721) / 721] x 100
Subtract the new number by the original number
521 - 721 = -200
-200 ÷ 721 = -0.27739251040221913
-0.27739251040221913 x 100 = -27.74%