-2.79% is the change from 215 to 209
Calculation steps:
[( 209 - 215 ) ÷ 215] x 100 = -2.79%
Formula
Percentage change = [(209 - 215) / 215] x 100
Subtract the new number by the original number
209 - 215 = -6
-6 ÷ 215 = -0.027906976744186046
-0.027906976744186046 x 100 = -2.79%