Percentage decrease = ((original value – new value) / original value) × 100
Subtract the new value from the original value
Divide the result by the original value
Multiply by 100 to get the percentage
Example: from 50 to 40
Percentage decrease = ((50 – 40) / 50) × 100
Percentage decrease = (10 / 50) × 100
Percentage decrease = 20%