-18.6% is the change from 387 to 315
Calculation steps:
[( 315 - 387 ) ÷ 387] x 100 = -18.6%
Formula
Percentage change = [(315 - 387) / 387] x 100
Subtract the new number by the original number
315 - 387 = -72
-72 ÷ 387 = -0.18604651162790697
-0.18604651162790697 x 100 = -18.6%