Holdings

Date          No.
1980           1 (2 copies)
1981           2
1982           3, 4
1983           5, 6
1984           7, 8
1985           9, 10
1986           11, 12
1987           13, 14
1988           15, 16
1989           17, 18
1990           19, 20
1991           21, 22
1992           23, 24
1993           25, 26
1994           28, 29
1995           29, 30
1996           31, 32
1997           33, 34
1998           35, 36
2000           37, 38, 39