1981   298.60 298.63 298.57 298.66 298.63 298.61 298.66 298.64 298.67 298.61 298.57 298.67 298.70 298.70 298.63
1982   298.83 298.85 298.78 298.81 298.79 298.82 298.75 298.87 298.84 298.84 298.81 298.89 298.82 298.80 298.84
1983   298.77 298.82 298.83 298.80 298.75 298.78 298.78 298.84 298.83 298.80 298.77 298.78 298.75 298.78 298.81
1984   298.48 298.47 298.53 298.47 298.62 298.52 298.49 298.53 298.59 298.54 298.61 298.58 298.56 298.54 298.60
1985   298.51 298.60 298.56 298.54 298.55 298.48 298.55 298.60 298.58 298.61 298.57 298.61 298.58 298.58 298.65
1986   298.57 298.56 298.56 298.62 298.54 298.57 298.60 298.60 298.70 298.67 298.61 298.69 298.62 298.67 298.68
1987   298.87 298.87 298.94 298.90 298.92 298.93 298.87 298.89 298.85 298.86 298.81 298.89 298.93 298.84 298.93
1988   298.66 298.64 298.74 298.74 298.72 298.77 298.69 298.63 298.73 298.67 298.67 298.64 298.64 298.75 298.67
1989   298.58 298.56 298.61 298.65 298.73 298.60 298.66 298.68 298.64 298.69 298.71 298.69 298.67 298.75 298.79
1990   298.67 298.67 298.67 298.73 298.70 298.74 298.74 298.77 298.81 298.69 298.68 298.72 298.76 298.74 298.77
1991   298.89 298.98 298.92 298.94 299.00 298.97 298.97 298.98 298.96 299.06 298.94 298.94 298.92 299.03 299.03
1992   298.66 298.72 298.73 298.69 298.74 298.74 298.71 298.81 298.76 298.73 298.72 298.78 298.74 298.71 298.76
1993   298.80 298.74 298.73 298.75 298.79 298.73 298.81 298.78 298.75 298.77 298.82 298.81 298.71 298.86 298.86
1994   298.67 298.61 298.64 298.67 298.69 298.63 298.63 298.67 298.62 298.67 298.61 298.58 298.64 298.65 298.69
1995   298.63 298.71 298.65 298.70 298.70 298.71 298.80 298.75 298.74 298.77 298.74 298.75 298.74 298.82 298.77
1996   298.54 298.63 298.59 298.61 298.71 298.61 298.58 298.64 298.72 298.70 298.57 298.58 298.65 298.66 298.69
1997   299.04 299.00 298.96 298.99 299.03 299.09 299.08 299.03 298.98 299.05 299.06 299.16 299.10 299.10 299.10
1998   298.73 298.75 298.78 298.75 298.74 298.76 298.76 298.82 298.81 298.82 298.87 298.83 298.80 298.85 298.86
1999   298.55 298.45 298.51 298.60 298.57 298.55 298.47 298.50 298.59 298.51 298.56 298.54 298.56 298.58 298.63
2000   298.50 298.44 298.56 298.50 298.51 298.61 298.46 298.52 298.56 298.60 298.49 298.57 298.55 298.61 298.56
2001   298.61 298.70 298.77 298.70 298.67 298.73 298.70 298.72 298.75 298.79 298.75 298.76 298.77 298.75 298.78
2002   298.65 298.73 298.80 298.72 298.66 298.82 298.91 298.91 298.91 298.97 298.86 298.95 298.91 299.04 298.87
2003   298.67 298.71 298.74 298.76 298.71 298.84 298.81 298.87 298.86 298.89 299.00 298.95 298.94 298.92 298.99
2004   298.68 298.77 298.74 298.80 298.83 298.79 298.79 298.74 298.72 298.84 298.83 298.81 298.81 298.74 298.81
2005   298.71 298.69 298.73 298.76 298.77 298.87 298.87 298.81 298.81 298.81 298.79 298.83 298.83 298.80 298.82
2006   298.82 298.76 298.86 298.82 298.76 298.74 298.75 298.87 298.71 298.77 298.78 298.80 298.84 298.84 298.90
2007   298.56 298.58 298.63 298.66 298.69 298.68 298.65 298.65 298.66 298.66 298.67 298.70 298.66 298.74 298.71
2008   298.77 298.69 298.77 298.65 298.77 298.72 298.73 298.66 298.70 298.75 298.79 298.76 298.73 298.79 298.79
2009   298.98 298.93 299.00 298.99 298.94 298.97 299.07 298.94 298.97 299.00 299.11 299.10 299.08 299.01 299.03