-81.02% is the change from 664 to 126
Calculation steps:
[( 126 - 664 ) ÷ 664] x 100 = -81.02%
Formula
Percentage change = [(126 - 664) / 664] x 100
Subtract the new number by the original number
126 - 664 = -538
-538 ÷ 664 = -0.8102409638554217
-0.8102409638554217 x 100 = -81.02%