-97.63% is the change from 633 to 15
Calculation steps:
[( 15 - 633 ) ÷ 633] x 100 = -97.63%
Formula
Percentage change = [(15 - 633) / 633] x 100
Subtract the new number by the original number
15 - 633 = -618
-618 ÷ 633 = -0.976303317535545
-0.976303317535545 x 100 = -97.63%