-7.6% is the change from 671 to 620
Calculation steps:
[( 620 - 671 ) ÷ 671] x 100 = -7.6%
Formula
Percentage change = [(620 - 671) / 671] x 100
Subtract the new number by the original number
620 - 671 = -51
-51 ÷ 671 = -0.07600596125186289
-0.07600596125186289 x 100 = -7.6%