6.94% is the change from 216 to 231
Calculation steps:
[( 231 - 216 ) ÷ 216] x 100 = 6.94%
Formula
Percentage change = [(231 - 216) / 216] x 100
Subtract the new number by the original number
231 - 216 = 15
15 ÷ 216 = 0.06944444444444445
0.06944444444444445 x 100 = 6.94%