| Year | Total Expenses | Average Net Price | 
|---|---|---|
| 2015 | $30,580 | $18,120 | 
| 2016 | $32,090 | $21,294 | 
| 2017 | $32,642 | $19,299 | 
| 2018 | $32,642 | $18,652 | 
| 2019 | $33,822 | $18,767 | 
| 2020 | $33,676 | $18,621 | 
| 2021* | $34,255 | $18,476 | 
| 2022* | $34,844 | $18,332 | 
| 2023* | $35,444 | $18,189 | 
| 2024* | $36,053 | $18,047 | 
| 2025* | $36,673 | $17,906 |