-78.53% is the change from 638 to 137
Calculation steps:
[( 137 - 638 ) ÷ 638] x 100 = -78.53%
Formula
Percentage change = [(137 - 638) / 638] x 100
Subtract the new number by the original number
137 - 638 = -501
-501 ÷ 638 = -0.7852664576802508
-0.7852664576802508 x 100 = -78.53%