-20.8% is the change from 351 to 278
Calculation steps:
[( 278 - 351 ) ÷ 351] x 100 = -20.8%
Formula
Percentage change = [(278 - 351) / 351] x 100
Subtract the new number by the original number
278 - 351 = -73
-73 ÷ 351 = -0.20797720797720798
-0.20797720797720798 x 100 = -20.8%