-79.1% is the change from 646 to 135
Calculation steps:
[( 135 - 646 ) ÷ 646] x 100 = -79.1%
Formula
Percentage change = [(135 - 646) / 646] x 100
Subtract the new number by the original number
135 - 646 = -511
-511 ÷ 646 = -0.7910216718266254
-0.7910216718266254 x 100 = -79.1%