| Sold | Grade | Monthly Average |
| Mar 2026 | 3.0 | $17.00 |
| Oct 2010 | 6.0 | $9.90 |
| Dec 2012 | 5.5 | $8.49 |
| May 2017 | 4.5 | $9.20 |
| Jun 2016 | 4.5 | $14.00 |
| Jan 2022 | 4.0 | $8.40 |
| Feb 2011 | 4.0 | $6.30 |
| Sep 2020 | 3.5 | $7.30 |
| Mar 2012 | 3.5 | $5.49 |
| Feb 2018 | 3.0 | $6.40 |
| Jun 2017 | 3.0 | $9.75 |
| May 2017 | 3.0 | $4.70 |
| Feb 2018 | 2.5 | $5.49 |
| Jan 2014 | 2.5 | $4.30 |
| Nov 2018 | 2.0 | $4.60 |
| Mar 2010 | 2.0 | $3.40 |
| Feb 2020 | 1.8 | $4.10 |