-2% is the change from 649 to 636
Calculation steps:
[( 636 - 649 ) ÷ 649] x 100 = -2%
Formula
Percentage change = [(636 - 649) / 649] x 100
Subtract the new number by the original number
636 - 649 = -13
-13 ÷ 649 = -0.020030816640986132
-0.020030816640986132 x 100 = -2%