-94.2% is the change from 517 to 30
Calculation steps:
[( 30 - 517 ) ÷ 517] x 100 = -94.2%
Formula
Percentage change = [(30 - 517) / 517] x 100
Subtract the new number by the original number
30 - 517 = -487
-487 ÷ 517 = -0.941972920696325
-0.941972920696325 x 100 = -94.2%