| | | No. of warrants | | Weighted average exercise price | | Exercise price range | | ||
| Outstanding at January 1, 2013 | | 18,863,261 | | $ | 3.11 | | | $0.94 – $5.06 | |
| Exercised during the year | | (435,783) | | $ | 1.36 | | | $0.94 – $1.76 | |
| Outstanding at December 31, 2013 | | 18,427,478 | | $ | 3.15 | | | $0.94 – $5.06 | |