Bar charts are proportional to record count, and scaled.

Publication Year	Count	Percent
1965	3	0.5
1966	0	0.0
1967	0	0.0
1968	6	0.9
1969	0	0.0
1970	3	0.5
1971	3	0.5
1972	3	0.5
1973	2	0.3
1974	1	0.2
1975	1	0.2
1976	5	0.8
1977	10	1.6
1978	15	2.3
1979	5	0.8
1980	14	2.2
1981	16	2.5
1982	14	2.2
1983	12	1.9
1984	13	2.0
1985	19	3.0
1986	35	5.5
1987	33	5.2
1988	22	3.4
1989	13	2.0
1990	33	5.2
1991	23	3.6
1992	21	3.3
1993	25	3.9
1994	33	5.2
1995	31	4.8
1996	45	7.0
1997	34	5.3
1998	22	3.4
1999	19	3.0
2000	22	3.4
2001	26	4.1
2002	21	3.3
2003	12	1.9
2004	14	2.2
2005	9	1.4
2006	2	0.3

Items: 42