-45.49% is the change from 510 to 278
Calculation steps:
[( 278 - 510 ) ÷ 510] x 100 = -45.49%
Formula
Percentage change = [(278 - 510) / 510] x 100
Subtract the new number by the original number
278 - 510 = -232
-232 ÷ 510 = -0.4549019607843137
-0.4549019607843137 x 100 = -45.49%