| Year | Total Expenses | Average Net Price | 
|---|---|---|
| 2015 | $25,000 | $18,934 | 
| 2016 | $20,422 | $13,487 | 
| 2017 | $20,722 | $13,560 | 
| 2018 | $20,722 | $14,814 | 
| 2019 | $22,845 | $14,311 | 
| 2020 | $26,450 | $17,916 | 
| 2021* | $26,839 | $18,013 | 
| 2022* | $27,233 | $18,110 | 
| 2023* | $27,634 | $18,208 | 
| 2024* | $28,040 | $18,306 | 
| 2025* | $28,452 | $18,405 |