-31.62% is the change from 971 to 664
Calculation steps:
[( 664 - 971 ) ÷ 971] x 100 = -31.62%
Formula
Percentage change = [(664 - 971) / 971] x 100
Subtract the new number by the original number
664 - 971 = -307
-307 ÷ 971 = -0.3161688980432544
-0.3161688980432544 x 100 = -31.62%