-18.42% is the change from 380 to 310
Calculation steps:
[( 310 - 380 ) ÷ 380] x 100 = -18.42%
Formula
Percentage change = [(310 - 380) / 380] x 100
Subtract the new number by the original number
310 - 380 = -70
-70 ÷ 380 = -0.18421052631578946
-0.18421052631578946 x 100 = -18.42%