-68.18% is the change from 660 to 210
Calculation steps:
[( 210 - 660 ) ÷ 660] x 100 = -68.18%
Formula
Percentage change = [(210 - 660) / 660] x 100
Subtract the new number by the original number
210 - 660 = -450
-450 ÷ 660 = -0.6818181818181818
-0.6818181818181818 x 100 = -68.18%