-90.77% is the change from 661 to 61
Calculation steps:
[( 61 - 661 ) ÷ 661] x 100 = -90.77%
Formula
Percentage change = [(61 - 661) / 661] x 100
Subtract the new number by the original number
61 - 661 = -600
-600 ÷ 661 = -0.9077155824508321
-0.9077155824508321 x 100 = -90.77%