| | | | Number of warrants | | Weighted average exercise price | | |
| Warrants outstanding at December 31, 2012 | | | 4,038,753 | | $ | 3.68 | |
| Issued | | | – | | | – | |
| Exercised | | | (3,117,928) | | | 3.75 | |
| Expired | | | – | | | – | |
| Warrants outstanding at December 31, 2013 | | | 920,825 | | $ | 3.44 | |