-1.97% is the change from 661 to 648
Calculation steps:
[( 648 - 661 ) ÷ 661] x 100 = -1.97%
Formula
Percentage change = [(648 - 661) / 661] x 100
Subtract the new number by the original number
648 - 661 = -13
-13 ÷ 661 = -0.019667170953101363
-0.019667170953101363 x 100 = -1.97%