-51.64% is the change from 641 to 310
Calculation steps:
[( 310 - 641 ) ÷ 641] x 100 = -51.64%
Formula
Percentage change = [(310 - 641) / 641] x 100
Subtract the new number by the original number
310 - 641 = -331
-331 ÷ 641 = -0.516380655226209
-0.516380655226209 x 100 = -51.64%