-6.75% is the change from 237 to 221
Calculation steps:
[( 221 - 237 ) ÷ 237] x 100 = -6.75%
Formula
Percentage change = [(221 - 237) / 237] x 100
Subtract the new number by the original number
221 - 237 = -16
-16 ÷ 237 = -0.06751054852320675
-0.06751054852320675 x 100 = -6.75%