-31.12% is the change from 331 to 228
Calculation steps:
[( 228 - 331 ) ÷ 331] x 100 = -31.12%
Formula
Percentage change = [(228 - 331) / 331] x 100
Subtract the new number by the original number
228 - 331 = -103
-103 ÷ 331 = -0.311178247734139
-0.311178247734139 x 100 = -31.12%