| Value | Category | Cases | |
|---|---|---|---|
| 99 | Don't Know | 0 |
0%
|
| 1987 | 2 |
0.6%
|
|
| 1989 | 2 |
0.6%
|
|
| 1993 | 5 |
1.4%
|
|
| 1994 | 2 |
0.6%
|
|
| 1996 | 4 |
1.2%
|
|
| 1997 | 3 |
0.9%
|
|
| 1998 | 2 |
0.6%
|
|
| 2000 | 8 |
2.3%
|
|
| 2001 | 5 |
1.4%
|
|
| 2002 | 10 |
2.9%
|
|
| 2003 | 8 |
2.3%
|
|
| 2004 | 12 |
3.5%
|
|
| 2005 | 14 |
4.1%
|
|
| 2006 | 7 |
2%
|
|
| 2007 | 11 |
3.2%
|
|
| 2008 | 5 |
1.4%
|
|
| 2009 | 27 |
7.8%
|
|
| 2010 | 21 |
6.1%
|
|
| 2011 | 16 |
4.6%
|
|
| 2012 | 19 |
5.5%
|
|
| 2013 | 26 |
7.5%
|
|
| 2014 | 23 |
6.7%
|
|
| 2015 | 35 |
10.1%
|
|
| 2016 | 25 |
7.2%
|
|
| 2017 | 35 |
10.1%
|
|
| 2018 | 18 |
5.2%
|
|
| Sysmiss | 6006 |