Year Number 1950 64.062 1951 64.406 1952 64.764 1953 64.762 1954 64.115 1955 62.864 1956 61.113 1957 59.649 1958 58.88 1959 59.097 1960 60.523 1961 60.875 1962 60.827 1963 61.381 1964 62.612 1965 64.252 1966 68.347 1967 72.284 1968 76.314 1969 80.337 1970 83.996 1971 85.577 1972 87.195 1973 88.492 1974 88.98 1975 88.455 1976 85.639 1977 82.244 1978 78.697 1979 75.433 1980 72.57 1981 69.909 1982 67.5 1983 65.389 1984 63.34 1985 61.239 1986 61.709 1987 61.152 1988 59.974 1989 58.583 1990 57.074 1991 53.471 1992 50.771 1993 48.772 1994 47.337 1995 46.615 1996 45.383 1997 44.452 1998 43.732 1999 43.003 2000 42.129 2001 41.717 2002 40.951 2003 40.206 2004 39.841 2005 39.924 2006 38.363 2007 37.146 2008 36.164 2009 35.177 2010 34.103 2011 33.867 2012 33.332 2013 32.74 2014 32.316 2015 32.09 2016 32.614 2017 33.251 2018 33.968 2019 34.615 2020 35.087 2021 35.598 2022 35.842 2023 35.919 2024 35.935 2025 35.92 2026 35.717 2027 35.491 2028 35.269 2029 35.051 2030 34.836 2031 34.755 2032 34.64 2033 34.552 2034 34.549 2035 34.651 2036 34.846 2037 35.108 2038 35.457 2039 35.867 2040 36.315 2041 36.79 2042 37.261 2043 37.797 2044 38.475 2045 39.324 2046 40.304 2047 41.387 2048 42.559 2049 43.762 2050 44.942 2051 46.051 2052 47.094 2053 48.079 2054 48.996 2055 49.827 2056 50.518 2057 51.069 2058 51.527 2059 51.933 2060 52.305 2061 52.606 2062 52.84 2063 53.027 2064 53.137 2065 53.15 2066 53.068 2067 52.878 2068 52.653 2069 52.475 2070 52.391 2071 52.424 2072 52.51 2073 52.676 2074 52.921 2075 53.231 2076 53.649 2077 54.111 2078 54.633 2079 55.217 2080 55.85 2081 56.575 2082 57.335 2083 58.112 2084 58.861 2085 59.544 2086 60.17 2087 60.716 2088 61.206 2089 61.657 2090 62.066 2091 62.397 2092 62.686 2093 62.948 2094 63.194 2095 63.429 2096 63.594 2097 63.743 2098 63.9 2099 64.091 2100 64.325