-84.57% is the change from 661 to 102
Calculation steps:
[( 102 - 661 ) ÷ 661] x 100 = -84.57%
Formula
Percentage change = [(102 - 661) / 661] x 100
Subtract the new number by the original number
102 - 661 = -559
-559 ÷ 661 = -0.8456883509833586
-0.8456883509833586 x 100 = -84.57%