<chart palette='2' bgColor='CCCCCC' showValues='0' xAxisName="Time Period" yAxisName="Drivers" formatNumberScale='1' numdivlines='3' labelDisplay='rotate' slantLabels='1'><set label="1991" value='9231405' /><set label="1992" value='9692974' /><set label="1993" value='10537677' /><set label="1994" value='10762041' /><set label="1995" value='11992578' /><set label="1996" value='12019156' /><set label="1997" value='12343598' /><set label="1998" value='12691835' /><set label="1999" value='13012132' /><set label="2000" value='13398895' /><set label="2001" value='14041846' /><set label="2002" value='14346373' /><set label="2003" value='14604720' /><set label="2004" value='14847416' /><set label="2005" value='15007005' /><set label="2006" value='15272680' /><set label="2007" value='15491878' /><set label="2008" value='15579603' /><set label="2009" value='15556658' /><set label="2010" value='15553387' /><set label="2011" value='15507284' /><set label="2012" value='15374230' /><set label="2013" value='15378206' /><set label="2014" value='15417032' /><set label="2015" value='15620312' /><set label="2016" value='15998416' /></chart>