-20.78% is the change from 664 to 526
Calculation steps:
[( 526 - 664 ) ÷ 664] x 100 = -20.78%
Formula
Percentage change = [(526 - 664) / 664] x 100
Subtract the new number by the original number
526 - 664 = -138
-138 ÷ 664 = -0.20783132530120482
-0.20783132530120482 x 100 = -20.78%