| Survey 1 | Survey 2 | Survey 3 | Survey 4 | Survey 5 | Survey 6 | Survey 7 | Survey 8 | Number of observation |
---|---|---|---|---|---|---|---|---|---|
Survey period ==> | Feb-Apr 2007 | Jul-Aug 2007 | Oct-Dec 2007&Mar-Apr 2008 | May-Aug 2008 | Sep 2008-Jan 2009 | Feb-May 2009 | Jun-Sep 2009 | Oct-Jan 2010 | Feb 2007-Sept 2009 |
Panel 1 | 615 | 507 | 378 | * | * | * | * | * | 1,500 |
Panel 2 | Â | 458 | 359 | 323 | * | * | * | * | 1,140 |
Panel 3 | Â | Â | 948 | 727 | 645 | * | * | * | 2,320 |
Panel 4 | Â | Â | Â | 968 | 814 | 696 | * | * | 2,478 |
Panel 5 | Â | Â | Â | Â | 479 | 398 | 333 | * | 1,210 |
Panel 6 | Â | Â | Â | Â | Â | 831 | 689 | 498 | 2,018 |
Total | 615 | 965 | 1,685 | 2,018 | 1,938 | 1,925 | 1,022 | 498 | 10,666 |