| Year | Total Expenses | Average Net Price | 
|---|---|---|
| 2015 | $25,835 | $16,698 | 
| 2016 | $26,366 | $17,854 | 
| 2017 | $27,336 | $16,830 | 
| 2018 | $27,336 | $17,654 | 
| 2019 | $28,598 | $19,355 | 
| 2020 | $30,637 | $21,394 | 
| 2021* | $31,764 | $22,874 | 
| 2022* | $32,933 | $24,457 | 
| 2023* | $34,145 | $26,150 | 
| 2024* | $35,402 | $27,959 | 
| 2025* | $36,705 | $29,894 |