-29.63% is the change from 908 to 639
Calculation steps:
[( 639 - 908 ) ÷ 908] x 100 = -29.63%
Formula
Percentage change = [(639 - 908) / 908] x 100
Subtract the new number by the original number
639 - 908 = -269
-269 ÷ 908 = -0.29625550660792954
-0.29625550660792954 x 100 = -29.63%