-99.7% is the change from 664 to 2
Calculation steps:
[( 2 - 664 ) ÷ 664] x 100 = -99.7%
Formula
Percentage change = [(2 - 664) / 664] x 100
Subtract the new number by the original number
2 - 664 = -662
-662 ÷ 664 = -0.9969879518072289
-0.9969879518072289 x 100 = -99.7%