-30.9% is the change from 971 to 671
Calculation steps:
[( 671 - 971 ) ÷ 971] x 100 = -30.9%
Formula
Percentage change = [(671 - 971) / 971] x 100
Subtract the new number by the original number
671 - 971 = -300
-300 ÷ 971 = -0.30895983522142123
-0.30895983522142123 x 100 = -30.9%