help finding pattern from sequence of numbers

-90: -70 =78%

-85: -68 =80%

-75: -65 =87%

-65: -58 =89%

-55: -50 =91%

-45: -45 =100%

-35: -35 =100%

0 : 0 =100%

35: 35 =100%

45: 45 =100%

55: 50 =91%

65: 58 =89%

75: 65 =87%

85: 68 =80%

90: 70 =78%

With this set of data, given a variable twist_r (representing the left side of colon), I am looking for a formula to get the right side of the colon (percentages (which are rough) are there to help). This data was taken from me approximating the actual value, but if your formula gets very similar values, it is acceptable then.

twist_r is any number from [-90,90], I only got a sample of them.

Does anyone know what it is?