| Year | Total Expenses | Average Net Price | 
|---|---|---|
| 2015 | $28,640 | $19,425 | 
| 2016 | $29,306 | $19,486 | 
| 2017 | $30,682 | $20,359 | 
| 2018 | $30,682 | $20,075 | 
| 2019 | $33,180 | $20,202 | 
| 2020 | $34,406 | $21,428 | 
| 2021* | $35,676 | $21,563 | 
| 2022* | $36,992 | $21,699 | 
| 2023* | $38,357 | $21,836 | 
| 2024* | $39,772 | $21,973 | 
| 2025* | $41,240 | $22,112 |