-2.86% is the change from 665 to 646
Calculation steps:
[( 646 - 665 ) ÷ 665] x 100 = -2.86%
Formula
Percentage change = [(646 - 665) / 665] x 100
Subtract the new number by the original number
646 - 665 = -19
-19 ÷ 665 = -0.02857142857142857
-0.02857142857142857 x 100 = -2.86%