Bar charts are proportional to record count, and scaled.

Publication Year	Count	Percent
1921	1	0.0
1922	4	0.1
1923	13	0.2
1924	24	0.4
1925	49	0.7
1926	110	1.7
1927	56	0.8
1928	51	0.8
1929	52	0.8
1930	48	0.7
1931	41	0.6
1932	45	0.7
1933	46	0.7
1934	37	0.6
1935	31	0.5
1936	44	0.7
1937	45	0.7
1938	46	0.7
1939	37	0.6
1940	31	0.5
1941	20	0.3
1942	12	0.2
1943	13	0.2
1944	7	0.1
1945	12	0.2
1946	24	0.4
1947	29	0.4
1948	58	0.9
1949	87	1.3
1950	89	1.3
1951	99	1.5
1952	85	1.3
1953	82	1.2
1954	81	1.2
1955	89	1.3
1956	81	1.2
1957	91	1.4
1958	96	1.4
1959	94	1.4
1960	83	1.3
1961	78	1.2
1962	91	1.4
1963	71	1.1
1964	71	1.1
1965	87	1.3
1966	93	1.4
1967	109	1.6
1968	85	1.3
1969	96	1.4
1970	83	1.3
1971	74	1.1
1972	108	1.6
1973	103	1.6
1974	82	1.2
1975	99	1.5
1976	75	1.1
1977	127	1.9
1978	102	1.5
1979	96	1.4
1980	85	1.3
1981	99	1.5
1982	116	1.7
1983	81	1.2
1984	88	1.3
1985	95	1.4
1986	89	1.3
1987	86	1.3
1988	78	1.2
1989	72	1.1
1990	99	1.5
1991	85	1.3
1992	84	1.3
1993	100	1.5
1994	98	1.5
1995	102	1.5
1996	128	1.9
1997	127	1.9
1998	133	2.0
1999	133	2.0
2000	156	2.4
2001	154	2.3
2002	199	3.0
2003	173	2.6
2004	172	2.6
2005	27	0.4

Items: 85