90.58% is the change from 520 to 991
Calculation steps:
[( 991 - 520 ) ÷ 520] x 100 = 90.58%
Formula
Percentage change = [(991 - 520) / 520] x 100
Subtract the new number by the original number
991 - 520 = 471
471 ÷ 520 = 0.9057692307692308
0.9057692307692308 x 100 = 90.58%