-31% is the change from 971 to 670
Calculation steps:
[( 670 - 971 ) ÷ 971] x 100 = -31%
Formula
Percentage change = [(670 - 971) / 971] x 100
Subtract the new number by the original number
670 - 971 = -301
-301 ÷ 971 = -0.309989701338826
-0.309989701338826 x 100 = -31%