-97.8% is the change from 501 to 11
Calculation steps:
[( 11 - 501 ) ÷ 501] x 100 = -97.8%
Formula
Percentage change = [(11 - 501) / 501] x 100
Subtract the new number by the original number
11 - 501 = -490
-490 ÷ 501 = -0.9780439121756487
-0.9780439121756487 x 100 = -97.8%