| Year | Total Expenses | Average Net Price | 
|---|---|---|
| 2015 | $17,260 | $10,929 | 
| 2016 | $18,200 | $11,726 | 
| 2017 | $19,967 | $13,323 | 
| 2018 | $19,967 | $14,420 | 
| 2019 | $20,879 | $14,681 | 
| 2020 | $21,818 | $15,620 | 
| 2021* | $22,815 | $16,759 | 
| 2022* | $23,858 | $17,980 | 
| 2023* | $24,948 | $19,291 | 
| 2024* | $26,088 | $20,698 | 
| 2025* | $27,280 | $22,206 |