very interesting. the weighting system has definitely changed. Apparently it's possible to add more than 1 point for honors classes. I had a similar unweight GPA, and was ranked somewhere around the top 30% in my high school, and still got into every state university I applied to (in engineering.)
Maybe things have changed a lot, but to me it's 1 of 2 things:
1) your school isn't as competitive as you think. State universities will know the top schools in state, and have um... special allowance for lower GPAs due to the competitiveness of the schools.
2) your grades are good enough to get in (assuming you're in the 98-99 percentile nationally on your standardized exams (which you are in math.)) but you don't realize it.