Traffic quarterly

Articles in SafetyLit
Y-Axis = Volume :: X-Axis = Issue
?=unknown status :: X=no issue published :: nn=articles from issue :: A=relevant article(s) IDed to add
S=searched, nothing relevant :: O=issue published but not yet searched :: C=combination issue

	1	2	3	4

1 (1947)	2	3	3	6
2 (1948)	1	7	4	3
3 (1949)	7	?	3	4
9 (1955)	?	2	1	4
10 (1956)	3	5	4	5
11 (1957)	4	4	5	5
12 (1958)	2	?	1	4
13 (1959)	1	2	1	2
14 (1960)	1	2	3	3
15 (1961)	1	1	?	6
16 (1962)	?	1	1	3
17 (1963)	2	3	1	2
19 (1965)	?	?	1	?
21 (1967)	?	1	?	?
32 (1978)	?	?	1	?