Year | Sample size | Initial survey sample | Study subsample | ||
---|---|---|---|---|---|
Response rate | Response rate | ||||
Crude | Corrected | Crude | Corrected | ||
1996 | 2000 | 75.4 | - | - | - |
1998 | 2000 | 66.1 | - | - | - |
2000 | 2000 | 68.8 | - | - | - |
2002 | 2000 | 66.9 | - | - | - |
2004 | 5000 | 61.5 | 63.4 | 62.3 | 64.0 |
2006 | 5000 | 57.3 | 59.2 | 58.3 | 60.1 |
2008 | 5000 | 60.1 | 62.2 | 60.4 | 62.6 |
2010 | 5000 | 60.5 | 62.3 | 61.6 | 63.6 |
2012 | 5000 | 59.4 | 62.0 | 60.6 | 63.4 |
2014 | 5000 | 51.5 | 53.3 | 53.2 | 55.1 |