-4.19% is the change from 215 to 206
Calculation steps:
[( 206 - 215 ) ÷ 215] x 100 = -4.19%
Formula
Percentage change = [(206 - 215) / 215] x 100
Subtract the new number by the original number
206 - 215 = -9
-9 ÷ 215 = -0.04186046511627907
-0.04186046511627907 x 100 = -4.19%