-87.44% is the change from 661 to 83
Calculation steps:
[( 83 - 661 ) ÷ 661] x 100 = -87.44%
Formula
Percentage change = [(83 - 661) / 661] x 100
Subtract the new number by the original number
83 - 661 = -578
-578 ÷ 661 = -0.8744326777609682
-0.8744326777609682 x 100 = -87.44%