-90.46% is the change from 671 to 64
Calculation steps:
[( 64 - 671 ) ÷ 671] x 100 = -90.46%
Formula
Percentage change = [(64 - 671) / 671] x 100
Subtract the new number by the original number
64 - 671 = -607
-607 ÷ 671 = -0.9046199701937406
-0.9046199701937406 x 100 = -90.46%