-16.72% is the change from 646 to 538
Calculation steps:
[( 538 - 646 ) ÷ 646] x 100 = -16.72%
Formula
Percentage change = [(538 - 646) / 646] x 100
Subtract the new number by the original number
538 - 646 = -108
-108 ÷ 646 = -0.16718266253869968
-0.16718266253869968 x 100 = -16.72%