-31.96% is the change from 97 to 66
Calculation steps:
[( 66 - 97 ) ÷ 97] x 100 = -31.96%
Formula
Percentage change = [(66 - 97) / 97] x 100
Subtract the new number by the original number
66 - 97 = -31
-31 ÷ 97 = -0.31958762886597936
-0.31958762886597936 x 100 = -31.96%