-87.95% is the change from 664 to 80
Calculation steps:
[( 80 - 664 ) ÷ 664] x 100 = -87.95%
Formula
Percentage change = [(80 - 664) / 664] x 100
Subtract the new number by the original number
80 - 664 = -584
-584 ÷ 664 = -0.8795180722891566
-0.8795180722891566 x 100 = -87.95%