-82.21% is the change from 815 to 145
Calculation steps:
[( 145 - 815 ) ÷ 815] x 100 = -82.21%
Formula
Percentage change = [(145 - 815) / 815] x 100
Subtract the new number by the original number
145 - 815 = -670
-670 ÷ 815 = -0.8220858895705522
-0.8220858895705522 x 100 = -82.21%