-23.45% is the change from 661 to 506
Calculation steps:
[( 506 - 661 ) ÷ 661] x 100 = -23.45%
Formula
Percentage change = [(506 - 661) / 661] x 100
Subtract the new number by the original number
506 - 661 = -155
-155 ÷ 661 = -0.2344931921331316
-0.2344931921331316 x 100 = -23.45%