-19.85% is the change from 806 to 646
Calculation steps:
[( 646 - 806 ) ÷ 806] x 100 = -19.85%
Formula
Percentage change = [(646 - 806) / 806] x 100
Subtract the new number by the original number
646 - 806 = -160
-160 ÷ 806 = -0.19851116625310175
-0.19851116625310175 x 100 = -19.85%