| Year | Total Expenses | Average Net Price | 
|---|---|---|
| 2015 | $21,969 | $14,970 | 
| 2016 | $22,586 | $14,836 | 
| 2017 | $23,249 | $14,945 | 
| 2018 | $23,249 | $14,054 | 
| 2019 | $24,445 | $15,019 | 
| 2020 | $25,334 | $15,908 | 
| 2021* | $26,079 | $16,024 | 
| 2022* | $26,846 | $16,141 | 
| 2023* | $27,635 | $16,259 | 
| 2024* | $28,447 | $16,378 | 
| 2025* | $29,284 | $16,497 |