-20.76% is the change from 838 to 664
Calculation steps:
[( 664 - 838 ) ÷ 838] x 100 = -20.76%
Formula
Percentage change = [(664 - 838) / 838] x 100
Subtract the new number by the original number
664 - 838 = -174
-174 ÷ 838 = -0.20763723150357996
-0.20763723150357996 x 100 = -20.76%