-1.7% is the change from 647 to 636
Calculation steps:
[( 636 - 647 ) ÷ 647] x 100 = -1.7%
Formula
Percentage change = [(636 - 647) / 647] x 100
Subtract the new number by the original number
636 - 647 = -11
-11 ÷ 647 = -0.017001545595054096
-0.017001545595054096 x 100 = -1.7%