My school, in Queensland, was the same. All of QLD schools were rated ona QCS/Average value. If they had more students doing Math C (higher level) and getting lower grades, it meant less than a Math A (easiest) getting a high grade. They didn't want students pulling down the schools over all rating.
I definitely saw this over the last year when we were required to take QCS- Queensland Core Skills Test, to determine our OP (overall position), that allowed us to get into University.
My school, in Queensland, was the same. All of QLD schools were rated ona QCS/Average value. If they had more students doing Math C (higher level) and getting lower grades, it meant less than a Math A (easiest) getting a high grade. They didn't want students pulling down the schools over all rating. I definitely saw this over the last year when we were required to take QCS- Queensland Core Skills Test, to determine our OP (overall position), that allowed us to get into University.