| Year | Total Expenses | Average Net Price |
|---|---|---|
| 2015 | $18,614 | $15,220 |
| 2016 | $18,810 | $16,006 |
| 2017 | $18,912 | $15,868 |
| 2018 | $18,912 | $15,658 |
| 2019 | $19,547 | $16,179 |
| 2020 | $19,437 | $16,069 |
| 2021* | $19,542 | $15,960 |
| 2022* | $19,647 | $15,851 |
| 2023* | $19,754 | $15,743 |
| 2024* | $19,860 | $15,636 |
| 2025* | $19,967 | $15,530 |