-85.25% is the change from 671 to 99
Calculation steps:
[( 99 - 671 ) ÷ 671] x 100 = -85.25%
Formula
Percentage change = [(99 - 671) / 671] x 100
Subtract the new number by the original number
99 - 671 = -572
-572 ÷ 671 = -0.8524590163934426
-0.8524590163934426 x 100 = -85.25%