-22.29% is the change from 830 to 645
Calculation steps:
[( 645 - 830 ) ÷ 830] x 100 = -22.29%
Formula
Percentage change = [(645 - 830) / 830] x 100
Subtract the new number by the original number
645 - 830 = -185
-185 ÷ 830 = -0.22289156626506024
-0.22289156626506024 x 100 = -22.29%