-68.57% is the change from 210 to 66
Calculation steps:
[( 66 - 210 ) ÷ 210] x 100 = -68.57%
Formula
Percentage change = [(66 - 210) / 210] x 100
Subtract the new number by the original number
66 - 210 = -144
-144 ÷ 210 = -0.6857142857142857
-0.6857142857142857 x 100 = -68.57%