-86.98% is the change from 507 to 66
Calculation steps:
[( 66 - 507 ) ÷ 507] x 100 = -86.98%
Formula
Percentage change = [(66 - 507) / 507] x 100
Subtract the new number by the original number
66 - 507 = -441
-441 ÷ 507 = -0.8698224852071006
-0.8698224852071006 x 100 = -86.98%