-89.47% is the change from 646 to 68
Calculation steps:
[( 68 - 646 ) ÷ 646] x 100 = -89.47%
Formula
Percentage change = [(68 - 646) / 646] x 100
Subtract the new number by the original number
68 - 646 = -578
-578 ÷ 646 = -0.8947368421052632
-0.8947368421052632 x 100 = -89.47%