-90.36% is the change from 664 to 64
Calculation steps:
[( 64 - 664 ) ÷ 664] x 100 = -90.36%
Formula
Percentage change = [(64 - 664) / 664] x 100
Subtract the new number by the original number
64 - 664 = -600
-600 ÷ 664 = -0.9036144578313253
-0.9036144578313253 x 100 = -90.36%