-16.64% is the change from 661 to 551
Calculation steps:
[( 551 - 661 ) ÷ 661] x 100 = -16.64%
Formula
Percentage change = [(551 - 661) / 661] x 100
Subtract the new number by the original number
551 - 661 = -110
-110 ÷ 661 = -0.1664145234493192
-0.1664145234493192 x 100 = -16.64%