-20.19% is the change from 837 to 668
Calculation steps:
[( 668 - 837 ) ÷ 837] x 100 = -20.19%
Formula
Percentage change = [(668 - 837) / 837] x 100
Subtract the new number by the original number
668 - 837 = -169
-169 ÷ 837 = -0.2019115890083632
-0.2019115890083632 x 100 = -20.19%