90.21% is the change from 521 to 991
Calculation steps:
[( 991 - 521 ) ÷ 521] x 100 = 90.21%
Formula
Percentage change = [(991 - 521) / 521] x 100
Subtract the new number by the original number
991 - 521 = 470
470 ÷ 521 = 0.9021113243761996
0.9021113243761996 x 100 = 90.21%