-18.82% is the change from 813 to 660
Calculation steps:
[( 660 - 813 ) ÷ 813] x 100 = -18.82%
Formula
Percentage change = [(660 - 813) / 813] x 100
Subtract the new number by the original number
660 - 813 = -153
-153 ÷ 813 = -0.1881918819188192
-0.1881918819188192 x 100 = -18.82%