1968	4	3.6	3.6	3.8	4
1969	1	3.4	3.5	3.8	3.8
1969	2	3.3	3.5	3.6	3.8
1969	3	3.5	3.6	3.8	3.9
1969	4	3.7	3.8	4.1	4.4
1970	1	3.6	4	4.3	4.4
1970	2	4.2	4.6	4.8	4.7
1970	3	4.8	5.1	5.2	5.1
1970	4	5.2	5.7	5.7	5.6
1971	1	5.8	6	5.8	5.7
1971	2	5.9	5.9	5.8	5.7
1971	3	6	5.9	5.7	5.5
1971	4	6	5.9	5.8	5.6
1972	1	6	5.8	5.7	5.5
1972	2	5.8	5.7	5.6	5.4
1972	3	5.8	5.6	5.4	5.3
1972	4	5.5	5.4	5.2	5.1
1973	1	5.3	5	4.9	4.9
1973	2	5	4.9	4.8	4.8
1973	3	4.8	4.8	4.9	5.1
1973	4	4.8	4.8	5.1	5.5
1974	1	4.7	5.3	5.6	5.9
1974	2	5.2	5.4	5.6	5.8
1974	3	5.1	5.4	5.7	5.8
1974	4	5.5	6.4	6.9	7.3
1975	1	6.5	8	8.5	8.3
1975	2	8.4	9	9.1	9
1975	3	8.9	8.6	8.5	8.4
1975	4	8.4	8.3	8.1	7.9
1976	1	8.4	7.9	7.7	7.5
1976	2	7.6	7.4	7.2	7
1976	3	7.4	7.3	7.1	6.9
1976	4	7.8	7.7	7.6	7.3
1977	1	8	7.8	7.5	7.3
1977	2	7.4	7.1	7	6.8
1977	3	7	6.9	6.8	6.7
1977	4	7	6.9	6.8	6.7
1978	1	6.8	6.4	6.3	6.3
1978	2	6.2	6.1	6	6
1978	3	5.9	6.1	6	6.1
1978	4	6	6	6.1	6.3
1979	1	5.8	5.9	6.1	6.4
1979	2	5.7	5.9	6.2	6.4
1979	3	5.7	6	6.5	7.1
1979	4	5.8	6.2	6.8	7.4
1980	1	5.9	6.3	6.6	7
1980	2	6.1	7.2	7.7	8
1980	3	7.5	8	8.3	8.5
1980	4	7.6	7.7	7.8	7.7
1981	1	7.5	7.6	7.7	7.6
1981	2	7.3	7.4	7.5	7.3
1981	3	7.4	7.2	7.5	7.6
1981	4	7.2	8.1	8.4	8.3
1982	1	8.4	8.9	9.1	9
1982	2	8.8	9.4	9.4	9.2
1982	3	9.5	9.8	9.6	9.3
1982	4	9.9	10.4	10.3	10.1
1983	1	10.7	10.5	10.3	10.1
1983	2	10.4	10.2	9.9	9.7
1983	3	10.1	9.5	9.2	9
1983	4	9.4	8.9	8.6	8.5
1984	1	8.5	8	7.9	7.7
1984	2	7.9	7.7	7.5	7.4
1984	3	7.5	7.3	7	6.9
1984	4	7.5	7.4	7.3	7.2
1985	1	7.2	7.2	7	7
1985	2	7.3	7.2	7.2	7.2
1985	3	7.3	7.3	7.3	7.3
1985	4	7.1	7.1	7.1	7.1
1986	1	7	6.8	6.8	6.7
1986	2	7.1	7	6.9	6.8
1986	3	7.2	7	7	6.9
1986	4	6.9	6.9	7	6.9
1987	1	6.8	6.8	6.8	6.7
1987	2	6.7	6.5	6.5	6.5
1987	3	6.2	6.1	6.1	6
1987	4	6	6	6.1	6.2
1988	1	5.9	5.9	6	6
1988	2	5.7	5.5	5.5	5.5
1988	3	5.4	5.4	5.4	5.5
1988	4	5.5	5.4	5.4	5.5
1989	1	5.3	5.3	5.4	5.5
1989	2	5.2	5.3	5.4	5.5
1989	3	5.3	5.3	5.4	5.4
1989	4	5.2	5.4	5.5	5.6
1990	1	5.3	5.4	5.5	5.5
1990	2	5.3	5.3	5.4	5.4
1990	3	5.3	5.5	5.6	5.9
1990	4	5.6	5.8	6.3	6.4
1991	1	5.9	6.3	6.7	6.9
1991	2	6.5	6.8	6.9	6.8
1991	3	6.8	6.9	6.8	6.6
1991	4	6.8	6.9	6.8	6.8
1992	1	7	7.1	7.1	6.9
1992	2	7.2	7.2	7.1	6.9
1992	3	7.5	7.6	7.5	7.3
1992	4	7.6	7.5	7.4	7.2
1993	1	7.3	7.2	7	6.9
1993	2	7	7	6.9	6.7
1993	3	7	6.9	6.8	6.7
1993	4	6.7	6.7	6.6	6.6
1994	1	6.5	6.7	6.5	6.4
1994	2	6.6	6.4	6.4	6.2
1994	3	6.1	6.1	6	6
1994	4	6	5.8	5.8	5.8
1995	1	5.6	5.5	5.4	5.4
1995	2	5.5	5.6	5.6	5.6
1995	3	5.7	5.7	5.7	5.7
1995	4	5.6	5.6	5.6	5.7
1996	1	5.6	5.7	5.7	5.8
1996	2	5.6	5.5	5.5	5.6
1996	3	5.4	5.4	5.4	5.4
1996	4	5.2	5.2	5.3	5.4
1997	1	5.3	5.3	5.3	5.3
1997	2	5.3	5	5.1	5.1
1997	3	4.9	4.8	4.9	5
1997	4	4.9	4.8	4.8	4.8
1998	1	4.7	4.7	4.7	4.7
1998	2	4.7	4.5	4.6	4.7
1998	3	4.4	4.5	4.5	4.6
1998	4	4.5	4.6	4.7	4.7
1999	1	4.4	4.4	4.4	4.5
1999	2	4.3	4.3	4.3	4.3
1999	3	4.3	4.3	4.3	4.4
1999	4	4.2	4.1	4.2	4.2
2000	1	4.1	4	4	4
2000	2	4.1	3.9	4	4
2000	3	4	4	4	4.1
2000	4	4	4	4.1	4.2
2001	1	4	4.2	4.4	4.5
2001	2	4.2	4.5	4.7	4.8
2001	3	4.5	4.7	4.9	5
2001	4	4.8	5.6	5.9	6
2002	1	5.6	5.8	6	6
2002	2	5.6	5.9	5.9	5.7
2002	3	5.9	6	6	5.8
2002	4	5.7	5.8	5.9	5.8
2003	1	5.9	6	6	5.9
2003	2	5.8	6	6	5.9
2003	3	6.2	6.2	6.1	6
2003	4	6.1	6	5.9	5.8
2004	1	5.9	5.7	5.6	5.5
2004	2	5.6	5.6	5.5	5.4
2004	3	5.6	5.5	5.5	5.4
2004	4	5.4	5.4	5.3	5.3
2005	1	5.4	5.3	5.2	5.2
2005	2	5.3	5.2	5.2	5.1
2005	3	5.1	5	5	4.9
2005	4	5	5	5	4.9
2006	1	4.9	4.8	4.8	4.8
2006	2	4.7	4.7	4.7	4.8