| Percentage | |||
| Length of employment, yrs | 2007 | 2008 | 2009 |
| –2 | 31 | 34 | 26 |
| 3–5 | 18 | 21 | 27 |
| 6–10 | 22 | 19 | 19 |
| 11–20 | 18 | 16 | 17 |
| 21– | 11 | 10 | 11 |
For co-workers in companies acquired, length of employment includes service years in the company acquired.
Average length of employment: 7.9 years (7.8 years).