Year Number 1960 9308 1961 9408 1962 9524 1963 9690 1964 9926 1965 10217 1966 10579 1967 11010 1968 11441 1969 11835 1970 12169 1971 12448 1972 12678 1973 12869 1974 13076 1975 13317 1976 13579 1977 13866 1978 14166 1979 14452 1980 14779 1981 15131 1982 15434 1983 15717 1984 15992 1985 16226 1986 16435 1987 16634 1988 16806 1989 16964 1990 17042 1991 17062 1992 17105 1993 17174 1994 17279 1995 17369 1996 17398 1997 17425 1998 17473 1999 17522 2000 17601 2001 17707 2002 17834 2003 17926 2004 17955 2005 17980 2006 18025 2007 18115 2008 18306 2009 18604 2010 18867 2011 19088 2012 19404 2013 19810 2014 20299 2015 20841 2016 21386 2017 21979 2018 22647 2019 23385 2020 24226 2021 25136 2022 26052 2023 26929