-31.63% is the change from 977 to 668
Calculation steps:
[( 668 - 977 ) ÷ 977] x 100 = -31.63%
Formula
Percentage change = [(668 - 977) / 977] x 100
Subtract the new number by the original number
668 - 977 = -309
-309 ÷ 977 = -0.3162743091095189
-0.3162743091095189 x 100 = -31.63%