-18.14% is the change from 816 to 668
Calculation steps:
[( 668 - 816 ) ÷ 816] x 100 = -18.14%
Formula
Percentage change = [(668 - 816) / 816] x 100
Subtract the new number by the original number
668 - 816 = -148
-148 ÷ 816 = -0.18137254901960784
-0.18137254901960784 x 100 = -18.14%