(in millions of US dollars except share and per-share amounts)
18. Contributed Surplus
| 2007 | 2006 | 2005 | ||||
| Balance, beginning of year | $ | 62.3 | $ | 36.3 | $ | 275.7 |
| Stock-based compensation | 36.6 | 26.0 | 24.9 | |||
| Share repurchases (Note 17) | – | – | (264.3) | |||
| Balance, end of year | $ | 98.9 | $ | 62.3 | $ | 36.3 |




