-21.45% is the change from 816 to 641
Calculation steps:
[( 641 - 816 ) ÷ 816] x 100 = -21.45%
Formula
Percentage change = [(641 - 816) / 816] x 100
Subtract the new number by the original number
641 - 816 = -175
-175 ÷ 816 = -0.21446078431372548
-0.21446078431372548 x 100 = -21.45%