-20.25% is the change from 637 to 508
Calculation steps:
[( 508 - 637 ) ÷ 637] x 100 = -20.25%
Formula
Percentage change = [(508 - 637) / 637] x 100
Subtract the new number by the original number
508 - 637 = -129
-129 ÷ 637 = -0.20251177394034536
-0.20251177394034536 x 100 = -20.25%