-6.05% is the change from 661 to 621
Calculation steps:
[( 621 - 661 ) ÷ 661] x 100 = -6.05%
Formula
Percentage change = [(621 - 661) / 661] x 100
Subtract the new number by the original number
621 - 661 = -40
-40 ÷ 661 = -0.060514372163388806
-0.060514372163388806 x 100 = -6.05%