| Year | Total Expenses | Average Net Price | 
|---|---|---|
| 2015 | $26,214 | $17,646 | 
| 2016 | $27,088 | $17,770 | 
| 2017 | $26,014 | $16,530 | 
| 2018 | $26,014 | $15,924 | 
| 2019 | $29,725 | $19,601 | 
| 2020 | $30,302 | $20,178 | 
| 2021* | $30,890 | $20,319 | 
| 2022* | $31,489 | $20,461 | 
| 2023* | $32,100 | $20,605 | 
| 2024* | $32,723 | $20,749 | 
| 2025* | $33,358 | $20,894 |