-89.49% is the change from 666 to 70
Calculation steps:
[( 70 - 666 ) ÷ 666] x 100 = -89.49%
Formula
Percentage change = [(70 - 666) / 666] x 100
Subtract the new number by the original number
70 - 666 = -596
-596 ÷ 666 = -0.8948948948948949
-0.8948948948948949 x 100 = -89.49%