Year,Replace_ratio,Replace_level
1960,,1
1961,,1
1962,,1
1963,,1
1964,,1
1965,,1
1966,,1
1967,,1
1968,1.011,1
1969,1.58,1
1970,0.736,1
1971,1.006,1
1972,1.454,1
1973,1.524,1
1974,0.527,1
1975,0.586,1
1976,3.416,1
1977,1.487,1
1978,0.908,1
1979,0.966,1
1980,0.56,1
1981,0.219,1
1982,0.394,1
1983,0.489,1
1984,0.27,1
1985,1.256,1
1986,0.903,1
1987,1.014,1
1988,1.516,1
1989,0.483,1
1990,0.769,1
1991,0.568,1
1992,0.863,1
1993,0.509,1
1994,0.446,1
1995,0.744,1
1996,1.129,1
1997,1.729,1
1998,1.289,1
1999,2.349,1
2000,0.945,1
2001,2.547,1
2002,1.406,1
2003,1.474,1
2004,1.084,1