| Year | Total Expenses | Average Net Price | 
|---|---|---|
| 2015 | $15,531 | $7,915 | 
| 2016 | $15,981 | $7,943 | 
| 2017 | $16,636 | $7,481 | 
| 2018 | $16,636 | $6,786 | 
| 2019 | $17,521 | $6,929 | 
| 2020 | $17,556 | $6,964 | 
| 2021* | $18,065 | $6,988 | 
| 2022* | $18,589 | $7,013 | 
| 2023* | $19,128 | $7,037 | 
| 2024* | $19,683 | $7,062 | 
| 2025* | $20,254 | $7,087 |