JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 1949 27.7 27.5 27.7 28.0 28.3 28.7 28.9 28.9 28.9 29.0 28.8 28.8 1950 28.0 28.0 28.2 28.5 28.7 29.0 29.4 28.3 28.7 28.7 28.8 29.0 1951 28.3 27.7 27.9 28.7 29.1 29.0 28.7 28.5 28.8 29.3 29.5 28.9 1952 28.5 28.1 28.1 28.6 28.6 29.3 29.1 28.7 28.9 29.3 29.1 28.6 1953 28.3 28.3 28.2 28.6 29.0 28.8 28.7 28.8 29.0 29.1 28.6 28.5 1954 28.2 28.1 28.1 28.6 29.0 29.1 29.2 29.5 29.3 29.3 29.0 28.6 1955 28.1 28.3 28.3 28.2 28.3 28.8 28.7 28.7 29.5 29.2 29.4 28.6 1956 28.1 28.1 28.1 28.5 28.9 28.7 28.9 28.9 28.9 29.0 29.0 28.7 1957 28.3 28.2 28.2 28.4 29.1 29.1 29.1 29.0 28.8 29.1 29.1 28.6 1958 28.1 27.9 27.9 28.4 28.8 28.7 28.7 28.7 28.9 29.0 29.0 28.6 1959 28.0 27.7 27.7 28.0 28.4 28.8 28.9 28.7 28.7 28.6 28.8 28.4 1960 28.0 27.9 28.1 28.1 28.8 29.0 29.2 29.0 29.1 29.2 29.4 28.5 1961 28.2 28.4 28.2 28.7 28.8 29.1 29.0 28.9 28.8 29.0 29.0 28.6 1962 28.5 28.2 28.3 28.8 29.0 29.3 29.5 29.4 29.2 29.4 28.8 28.7 1963 28.5 28.3 28.8 28.9 29.2 29.4 29.4 29.2 29.1 29.0 29.2 29.3 1964 28.3 28.0 28.3 28.8 29.1 29.2 29.2 29.0 29.2 29.3 29.0 28.7 1965 28.2 27.8 28.1 28.6 28.8 28.8 28.3 28.6 28.6 28.6 28.8 28.4 1966 27.5 27.4 27.7 28.4 28.6 29.1 29.2 29.1 29.1 29.4 29.1 28.7 1967 28.2 28.0 28.0 28.6 29.1 29.3 29.1 28.9 29.0 28.9 28.5 28.4 1968 28.3 28.1 28.1 28.5 29.0 29.7 29.7 29.4 29.3 29.4 28.9 28.5 1969 28.0 27.8 28.1 28.7 29.0 29.2 29.0 28.9 29.2 29.4 29.1 28.8 1970 28.7 28.3 28.4 28.7 29.1 29.4 29.4 29.2 29.6 29.7 29.5 29.0 1971 28.8 28.4 28.7 28.8 29.1 28.9 28.9 28.9 29.2 29.0 28.9 28.7 1972 28.5 28.2 28.3 28.5 29.0 28.9 28.8 28.5 28.7 28.9 29.0 28.5 1973 28.0 28.0 28.1 28.5 28.9 29.2 29.3 29.5 29.5 29.3 29.2 29.0 1974 28.6 28.5 28.2 28.5 28.9 28.9 29.1 29.0 29.1 29.4 29.0 28.6 1975 28.2 27.9 28.1 28.6 28.9 29.0 29.2 29.0 29.3 29.1 29.0 28.9 1976 28.8 28.3 28.4 28.4 28.7 28.7 28.9 28.7 28.5 29.1 29.1 28.6 1977 28.4 28.1 28.3 28.5 29.1 29.3 29.1 28.9 29.0 29.1 29.2 29.0 1978 28.3 27.9 28.0 28.4 29.1 29.5 29.7 29.4 29.3 29.3 29.0 28.8 1979 28.5 28.3 28.3 28.6 29.0 29.3 29.0 28.9 29.3 28.9 29.1 28.7 1980 28.1 27.9 28.1 28.5 29.0 29.1 28.9 29.0 29.1 29.2 29.3 29.2 1981 28.6 28.2 28.4 28.8 29.7 29.6 29.6 29.2 29.3 29.4 29.5 29.0 1982 28.7 28.6 28.5 28.8 29.1 29.3 28.7 28.6 28.6 28.9 29.1 28.6 1983 27.9 27.6 27.9 28.3 28.6 29.2 29.0 29.1 29.3 29.3 29.3 29.0 1984 28.7 28.6 28.7 29.0 29.5 29.3 29.5 29.3 29.5 29.3 29.1 28.8 1985 28.3 28.2 28.4 28.9 29.2 29.4 29.1 29.2 29.2 29.1 29.4 29.1 1986 28.6 28.2 28.5 28.9 29.5 29.5 29.2 29.1 28.9 29.3 29.2 28.7 1987 28.1 27.8 28.2 28.8 29.4 29.6 29.2 29.2 29.2 29.3 29.4 29.1 1988 28.5 28.2 28.5 29.1 29.4 29.6 29.6 29.6 29.7 29.6 29.4 29.1 1989 28.8 28.7 28.7 29.1 29.2 29.2 29.3 29.3 29.5 29.6 29.3 28.8 1990 28.5 28.2 28.3 28.8 29.3 29.3 29.1 29.2 29.0 29.3 28.9 28.2 1991 28.0 27.6 28.0 28.6 29.0 29.3 29.2 29.0 28.9 28.8 28.9 28.4 1992 27.9 27.7 27.7 28.5 29.1 29.3 28.9 29.0 29.1 29.3 28.8 28.5 1993 27.8 27.7 28.0 28.4 28.8 29.0 29.0 28.7 28.9 28.9 29.2 28.8 1994 28.2 28.3 28.5 29.0 29.3 29.4 29.1 29.2 29.1 29.2 29.2 28.6 1995 28.1 28.1 28.0 28.5 29.2 29.5 29.6 29.8 29.7 29.8 29.7 29.4 1996 28.8 28.5 28.6 29.1 29.5 29.6 29.8 29.7 29.8 29.9 29.4 29.0 1997 28.6 28.3 28.1 28.8 29.3 29.6 29.3 28.7 28.9 29.5 29.2 29.0 1998 28.1 27.8 28.0 28.5 29.1 29.5 29.8 29.9 30.1 29.9 29.7 29.4 1999 29.1 29.0 29.1 29.1 29.5 29.4 29.5 29.3 29.5 29.7 29.5 29.3 2000 29.1 28.9 29.0 29.3 29.6 29.6 29.5 29.6 29.6 29.7 29.7 29.4 2001 29.2 28.8 28.8 29.5 29.7 29.9 29.5 29.4 29.6 29.9 29.7 29.1 2002 28.7 28.4 28.6 29.2 29.6 29.6 29.2 29.0 29.2 29.5 29.6 29.0 2003 28.5 28.2 28.5 29.2 29.5 29.6 29.5 29.3 29.3 29.7 29.6 29.1 2004 28.8 28.7 29.0 29.2 29.5 29.2 29.3 28.9 29.3 29.3 29.5 29.2 2005 28.6 28.1 28.5 28.8 29.3 29.5 29.6 29.3 29.3 29.7 29.5 29.2 2006 28.9 28.7 28.7 29.0 29.4 29.8 29.2 28.9 29.5 29.2 29.4 29.2 2007 28.6 28.4 28.4 29.0 29.5 29.8 29.7 29.5 29.8 29.7 29.6 29.4 2008 29.0 28.7 28.7 29.1 29.3 29.3 29.5 29.7 29.8 29.8 29.5 29.4 2009 29.1 28.9 28.8 29.2 29.6 29.7 29.6 29.5 29.4 29.4 29.5 29.0 2010 28.5 28.1 28.6 29.1 29.6 30.1 30.0 29.8 29.8 29.9 29.9 29.7 2011 29.5 29.4 29.2 29.4 29.6 29.5 29.2 29.2 29.4 29.5 29.7 29.4 2012 29.0 28.9 28.8 29.2 29.8 29.5 29.5 29.3 29.5 29.4 29.5 29.3 2013 28.9 28.6 28.9 29.2 29.7 29.8 29.8 29.7 29.9 29.5 29.4 29.5 2014 29.1 28.9 28.9 29.2 29.8 30.2 29.6 29.6 29.5 29.6 29.8 29.4 2015 29.0 28.4 28.3 29.0 29.4 29.5 29.2 29.1 29.3 29.2 29.4 29.0 2016 28.5 28.2 28.5 29.0 29.7 30.2 30.1 29.8 30.1 30.0 29.8 29.5 2017 29.1 28.8 29.0 29.3 29.8 30.0 30.0 30.3 30.3 30.1 30.0 29.7 2018 29.3 29.1 29.1 29.2 29.9 29.9 29.6 29.4 29.4 29.8 29.6 29.2 2019 28.5 28.2 28.4 28.9 29.7 29.9 29.8 29.4 29.5 29.8 29.7 29.2 2020 28.8 28.6 28.8 29.5 29.7 30.2 30.2 30.2 30.4 30.3 30.1 29.7 2021 29.4 29.1 29.2 29.5 99.9 99.9 99.9 99.9 99.9 99.9 99.9 99.9