| Year | Total Expenses | Average Net Price |
|---|---|---|
| 2011 | $11,680 | $6,568 |
| 2012 | $11,650 | $6,137 |
| 2013 | $12,776 | $7,263 |
| 2014 | $13,322 | $7,961 |
| 2015 | $13,737 | $8,376 |
| 2016 | $14,103 | $8,349 |
| 2017* | $14,543 | $8,784 |
| 2018* | $14,997 | $9,242 |
| 2019* | $15,465 | $9,723 |
| 2020* | $15,947 | $10,230 |
| 2021* | $16,445 | $10,763 |
