-82.17% is the change from 645 to 115
Calculation steps:
[( 115 - 645 ) ÷ 645] x 100 = -82.17%
Formula
Percentage change = [(115 - 645) / 645] x 100
Subtract the new number by the original number
115 - 645 = -530
-530 ÷ 645 = -0.8217054263565892
-0.8217054263565892 x 100 = -82.17%