((y2 - y1) / y1)*100 = your percent change. y1 is the original value, and y2 is the value it changed to.

Using the formula for percentage change, and following the order of operations

- Subtract (12.97 - 159.59) which gives you: -146.62
- Divide -146.62 / 159.59 which gives you: -0.9187292436
- Multiply -0.9187292436 * 100 = -91.87292436