-87.58% is the change from 660 to 82
Calculation steps:
[( 82 - 660 ) ÷ 660] x 100 = -87.58%
Formula
Percentage change = [(82 - 660) / 660] x 100
Subtract the new number by the original number
82 - 660 = -578
-578 ÷ 660 = -0.8757575757575757
-0.8757575757575757 x 100 = -87.58%