Behaviour change

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

6 (1989)	?	?	?	2	C
14 (1997)	?	1	?	?	1
17 (2000)	?	2	?	1	?
20 (2003)	?	?	1	?	?
21 (2004)	?	?	?	?	1
22 (2005)	?	?	?	1	?
24 (2007)	?	1	?	?	?
24 (2023)	1	?	?	?	?
26 (2009)	?	1	1	1	?
27 (2010)	?	1	?	?	?
30 (2013)	?	1	?	?	?
38 (2021)	?	?	?	1	?