-16.59% is the change from 645 to 538
Calculation steps:
[( 538 - 645 ) ÷ 645] x 100 = -16.59%
Formula
Percentage change = [(538 - 645) / 645] x 100
Subtract the new number by the original number
538 - 645 = -107
-107 ÷ 645 = -0.16589147286821707
-0.16589147286821707 x 100 = -16.59%