調查日期 <br> Date of survey	18 - 29	30+	整體  <br>Overall
7-12/1997	15.1%	22.2%	19.9%
1-6/1998	15.3%	18.5%	17.5%
7-12/1998	12.3%	18.8%	16.8%
1-6/1999	10.2%	15.0%	13.2%
7-12/1999	12.7%	18.5%	17.0%
1-6/2000	10.3%	17.5%	15.9%
7-12/2000	11.1%	15.2%	14.2%
1-6/2001	10.9%	15.9%	14.7%
7-12/2001	10.9%	15.5%	14.0%
1-6/2002	11.2%	16.9%	15.5%
7-12/2002	10.9%	16.0%	14.7%
1-6/2003	9.7%	15.2%	13.5%
7-12/2003	12.8%	16.9%	15.6%
1-6/2004	11.3%	16.2%	14.3%
7-12/2004	13.1%	17.4%	16.2%
1-6/2005	8.4%	17.9%	14.7%
7-12/2005	13.5%	18.1%	16.9%
1-6/2006	10.2%	16.1%	14.9%
7-12/2006	8.3%	22.8%	20.1%
1-6/2007	12.1%	17.5%	16.7%
7-12/2007	9.6%	17.8%	16.0%
1-6/2008	12.2%	13.4%	13.3%
7-12/2008	9.3%	14.0%	13.0%
1-6/2009	6.2%	15.1%	13.3%
7-12/2009	7.6%	14.3%	13.1%
1-6/2010	11.7%	15.5%	14.8%
7-12/2010	7.5%	15.5%	13.8%
1-6/2011	4.5%	12.4%	10.3%
7-12/2011	8.8%	20.7%	17.8%
1-6/2012	5.9%	13.1%	11.7%
7-12/2012	8.2%	18.1%	16.2%
1-6/2013	6.0%	13.4%	12.0%
7-12/2013	4.7%	17.4%	15.0%
1-6/2014	9.7%	12.2%	11.6%
7-12/2014	11.0%	16.0%	15.0%	
1-6/2015	7.7%	14.2%	13.1%	
7-12/2015	5.6%	14.7%	13.2%