Year Number 1987 0.8837890625 1988 1.1085136218 1989 1.3332381811 1990 1.5579627404 1991 1.7826872997 1992 2.007411859 1993 2.2321364183 1994 2.4568609776 1995 2.6815855369 1996 2.9063100962 1997 3.1310346554 1998 3.3557592147 1999 3.580483774 2000 3.8052083333 2001 4.0055338542 2002 4.205859375 2003 4.235546875 2004 4.265234375 2005 4.294921875 2006 4.294921875 2007 4.294921875 2008 4.294921875 2009 4.294921875 2010 4.294921875 2011 4.294921875 2012 4.294921875 2013 4.294921875 2014 4.294921875 2015 4.294921875 2016 4.294921875 2017 4.294921875 2018 4.294921875 2019 4.294921875 2020 4.294921875