-97.55% is the change from 611 to 15
Calculation steps:
[( 15 - 611 ) ÷ 611] x 100 = -97.55%
Formula
Percentage change = [(15 - 611) / 611] x 100
Subtract the new number by the original number
15 - 611 = -596
-596 ÷ 611 = -0.9754500818330606
-0.9754500818330606 x 100 = -97.55%