-3.21% is the change from 655 to 634
Calculation steps:
[( 634 - 655 ) ÷ 655] x 100 = -3.21%
Formula
Percentage change = [(634 - 655) / 655] x 100
Subtract the new number by the original number
634 - 655 = -21
-21 ÷ 655 = -0.03206106870229008
-0.03206106870229008 x 100 = -3.21%