| Weighted class | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | Average 2010/15 |
| 0% | 54% | 59% | 65% | 56% | 56% | 49% | 57% |
| 20% | 12% | 11% | 7% | 16% | 18% | 12% | 13% |
| 35% | 6% | 3% | 2% | 7% | 5% | 7% | 5% |
| 50% | 3% | 3% | 4% | 2% | 2% | 2% | 3% |
| 75% | 8% | 5% | 5% | 5% | 6% | 6% | 6% |
| 100% | 16% | 18% | 16% | 13% | 11% | 21% | 16% |
| 150% | 1% | 1% | 1% | 1% | 2% | 3% | 2% |
| Total | 100% | 100% | 100% | 100% | 100% | 100% | 100% |