| Sold | Grade | Monthly Average |
| Dec 2010 | 6.0 | $5.40 |
| May 2020 | 5.0 | $4.80 |
| Jan 2019 | 4.5 | $4.40 |
| Aug 2023 | 4.0 | $4.00 |
| Jan 2023 | 4.0 | $4.00 |
| Mar 2019 | 4.0 | $4.40 |
| Nov 2016 | 4.0 | $3.60 |
| Oct 2013 | 4.0 | $2.80 |
| May 2013 | 4.0 | $2.80 |
| Jun 2012 | 4.0 | $2.80 |
| Dec 2015 | 3.0 | $1.99 |
| Apr 2016 | 2.5 | $1.60 |
| Jun 2015 | 2.0 | $1.40 |