-92.72% is the change from 206 to 15
Calculation steps:
[( 15 - 206 ) ÷ 206] x 100 = -92.72%
Formula
Percentage change = [(15 - 206) / 206] x 100
Subtract the new number by the original number
15 - 206 = -191
-191 ÷ 206 = -0.9271844660194175
-0.9271844660194175 x 100 = -92.72%