Year,Spring_kg_tow,Fall_kg_tow,B_thresh
1963,,,
1964,,,
1965,,0.8847,2.77
1966,,0.6153,2.77
1967,,0.4657,2.77
1968,,0.2967,2.77
1969,0.8767,0.3190,2.77
1970,1.0867,0.2030,2.77
1971,1.2833,0.1980,2.77
1972,1.2133,0.2690,2.77
1973,1.3767,0.4227,2.77
1974,1.9200,0.6143,2.77
1975,1.7333,1.1360,2.77
1976,2.4967,1.3070,2.77
1977,2.4900,1.4457,2.77
1978,2.7733,1.0317,2.77
1979,1.6867,0.8033,2.77
1980,1.1200,0.6623,2.77
1981,1.0000,0.8817,2.77
1982,0.6467,0.9360,2.77
1983,0.4600,0.7823,2.77
1984,0.2433,0.3817,2.77
1985,0.6767,0.5923,2.77
1986,0.9800,0.6233,2.77
1987,1.1000,0.4873,2.77
1988,0.6567,0.1143,2.77
1989,0.3567,0.0723,2.77
1990,0.2633,0.1557,2.77
1991,0.3333,0.1993,2.77
1992,0.3233,0.4073,2.77
1993,0.1833,0.3220,2.77
1994,0.1533,0.2790,2.77
1995,0.0567,0.0653,2.77
1996,0.0833,0.0933,2.77
1997,0.0600,0.1220,2.77
1998,0.0833,0.0950,2.77
1999,0.0833,0.1320,2.77
2000,0.2467,0.5513,2.77
2001,3.2967,0.8363,2.77
2002,3.3100,1.0270,2.77
2003,3.7367,0.6793,2.77
2004,0.6900,0.4373,2.77
2005,1.3150,0.1747,2.77
2006,,0.1600,2.77