634.44% is the change from 90 to 661
Calculation steps:
[( 661 - 90 ) ÷ 90] x 100 = 634.44%
Formula
Percentage change = [(661 - 90) / 90] x 100
Subtract the new number by the original number
661 - 90 = 571
571 ÷ 90 = 6.344444444444444
6.344444444444444 x 100 = 634.44%