-15.38% is the change from 390 to 330
Calculation steps:
[( 330 - 390 ) ÷ 390] x 100 = -15.38%
Formula
Percentage change = [(330 - 390) / 390] x 100
Subtract the new number by the original number
330 - 390 = -60
-60 ÷ 390 = -0.15384615384615385
-0.15384615384615385 x 100 = -15.38%