Year,Exploit_index,Spring_kg_tow,B_index_kg_tow_MA_3
1968,,0.03990662,
1969,,0.023849198,0.041984255
1970,,0.062196947,0.040777192
1971,,0.036285432,0.068916414
1972,,0.108266863,0.091939575
1973,,0.131266431,0.249488814
1974,,0.508933148,0.292409677
1975,,0.237029453,0.366990552
1976,,0.355009055,0.247038622
1977,,0.14907736,0.232440084
1978,,0.193233837,0.1486649
1979,,0.103683504,0.143561131
1980,,0.133766052,0.133667088
1981,16.05092553,0.163551708,0.105518042
1982,64.48320972,0.019236365,0.087880982
1983,51.33327952,0.080854872,0.065753068
1984,26.03549931,0.097167968,0.098021108
1985,17.68431979,0.116040485,0.141981379
1986,42.37951054,0.212735683,0.177482177
1987,13.50237694,0.203670361,0.205200437
1988,19.56128206,0.199195267,0.16246608
1989,22.94818587,0.08453261,0.122767626
1990,39.27813407,0.084574999,0.072421396
1991,27.83910721,0.04815658,0.113505216
1992,25.82424665,0.207784069,0.098844675
1993,35.42984895,0.040593375,0.102363079
1994,33.21001052,0.058711792,0.068777446
1995,43.84332946,0.107027172,0.085615143
1996,30.36942824,0.091106466,0.111179008
1997,33.74886776,0.135403387,0.092787013
1998,12.39681019,0.051851185,0.1363068
1999,15.02222249,0.221665827,0.136840844
2000,15.26733722,0.13700552,0.197981163
2001,7.312097159,0.235272143,0.329914853
2002,7.022971104,0.617466897,0.452262691
2003,5.325436438,0.504049034,0.480746646
2004,7.818996281,0.320724007,0.399451633
2005,19.43272087,0.373581857,0.32740511
2006,,0.287909464,