-68.52% is the change from 664 to 209
Calculation steps:
[( 209 - 664 ) ÷ 664] x 100 = -68.52%
Formula
Percentage change = [(209 - 664) / 664] x 100
Subtract the new number by the original number
209 - 664 = -455
-455 ÷ 664 = -0.6852409638554217
-0.6852409638554217 x 100 = -68.52%