| Year | Total Expenses | Average Net Price |
|---|---|---|
| 2015 | $22,416 | $18,834 |
| 2016 | $22,656 | $19,086 |
| 2017 | $22,944 | $19,530 |
| 2018 | $22,944 | $19,910 |
| 2019 | $24,124 | $21,160 |
| 2020 | $24,584 | $21,620 |
| 2021* | $24,896 | $22,089 |
| 2022* | $25,212 | $22,568 |
| 2023* | $25,533 | $23,058 |
| 2024* | $25,857 | $23,559 |
| 2025* | $26,185 | $24,070 |