-19.57% is the change from 797 to 641
Calculation steps:
[( 641 - 797 ) ÷ 797] x 100 = -19.57%
Formula
Percentage change = [(641 - 797) / 797] x 100
Subtract the new number by the original number
641 - 797 = -156
-156 ÷ 797 = -0.19573400250941028
-0.19573400250941028 x 100 = -19.57%