-38.1% is the change from 819 to 507
Calculation steps:
[( 507 - 819 ) ÷ 819] x 100 = -38.1%
Formula
Percentage change = [(507 - 819) / 819] x 100
Subtract the new number by the original number
507 - 819 = -312
-312 ÷ 819 = -0.38095238095238093
-0.38095238095238093 x 100 = -38.1%