I did an IQ test. Paid for it. According to the internet it's inflated by as much as 21 points. My question is about simple math.

Maximum score: 166 ( -21 ) = 145

1. My score: 155 ( -21 ) =134

2. 155:166= 0.934 * 145 = 135.4

Why is there a difference between 1 and 2 and what is my real score?