-19.12% is the change from 816 to 660
Calculation steps:
[( 660 - 816 ) ÷ 816] x 100 = -19.12%
Formula
Percentage change = [(660 - 816) / 816] x 100
Subtract the new number by the original number
660 - 816 = -156
-156 ÷ 816 = -0.19117647058823528
-0.19117647058823528 x 100 = -19.12%