-91.25% is the change from 343 to 30
Calculation steps:
[( 30 - 343 ) ÷ 343] x 100 = -91.25%
Formula
Percentage change = [(30 - 343) / 343] x 100
Subtract the new number by the original number
30 - 343 = -313
-313 ÷ 343 = -0.9125364431486881
-0.9125364431486881 x 100 = -91.25%