-86.7% is the change from 609 to 81
Calculation steps:
[( 81 - 609 ) ÷ 609] x 100 = -86.7%
Formula
Percentage change = [(81 - 609) / 609] x 100
Subtract the new number by the original number
81 - 609 = -528
-528 ÷ 609 = -0.8669950738916257
-0.8669950738916257 x 100 = -86.7%