-31.2% is the change from 936 to 644
Calculation steps:
[( 644 - 936 ) ÷ 936] x 100 = -31.2%
Formula
Percentage change = [(644 - 936) / 936] x 100
Subtract the new number by the original number
644 - 936 = -292
-292 ÷ 936 = -0.31196581196581197
-0.31196581196581197 x 100 = -31.2%