2.3% is the change from 391 to 400
Calculation steps:
[( 400 - 391 ) ÷ 391] x 100 = 2.3%
Formula
Percentage change = [(400 - 391) / 391] x 100
Subtract the new number by the original number
400 - 391 = 9
9 ÷ 391 = 0.023017902813299233
0.023017902813299233 x 100 = 2.3%