-9.09% is the change from 66 to 60
Calculation steps:
[( 60 - 66 ) ÷ 66] x 100 = -9.09%
Formula
Percentage change = [(60 - 66) / 66] x 100
Subtract the new number by the original number
60 - 66 = -6
-6 ÷ 66 = -0.09090909090909091
-0.09090909090909091 x 100 = -9.09%