Wave | Survey year | Number of respondentsa | Ages of respondents | Response rate (%) | Attrition rate (%) |
---|---|---|---|---|---|
1 | 2005 | 34,240 | 50–59 | 83.8 | – |
2 | 2006 | 32,285 | 51–60 | 92.2 | 5.7 |
3 | 2007 | 30,730 | 52–61 | 95.4 | 4.8 |
4 | 2008 | 29,605 | 53–62 | 96.2 | 3.7 |
5 | 2009 | 28,736 | 54–63 | 97.3 | 2.9 |
6 | 2010 | 26,220 | 55–64 | 91.8 | 8.8 |
7 | 2011 | 25,321 | 56–65 | 90.0 | 3.4 |
8 | 2012 | 24,026 | 57–66 | 90.9 | 5.1 |
9 | 2013 | 23,722 | 58–67 | 93.9 | 1.3 |
10 | 2014 | 22,748 | 59–68 | 93.9 | 4.1 |