Bestandslücken
[N=1951,28-34; 1952; 1959-1972; 1973,505-506,508,518,521,528; 1974,540-550,552; 1975,553,563-564,566,570; 1977,613-614,622,624; 1978,632,634-635,644-645; 1979,657,663-664; 1980,683; 1981,691,694; 1982,700,702,704-706,708,711-714; 1985,734,738,739; 1986,745,750,754-75; 1987,760,762; 1991,815]