Improvement analysis of article quality in World Journal of Gastroenterology during 2008-2012

Table 2 Co-author collaboration status in World Journal of Gastroenterology in 2008-2012

Year	Distribution of number of co-author articles											Total (articles)	Authors	Cooperation degree	Cooperation rate
	1	2	3	4	5	6	7	8	9	10	≥11
2008	49	96	91	147	154	167	111	121	63	42	71	1112	6501	5.85	95.59%
2009	28	66	100	102	139	107	107	74	46	38	56	863	5072	5.88	96.76%
2010	28	62	77	84	113	108	108	74	53	46	106	813	5037	6.20	96.56%
2011	21	46	63	77	103	87	100	96	29	25	30	677	4034	5.96	96.90%
2012	31	67	86	122	95	137	111	91	57	57	90	944	5956	6.31	96.72%
Total	157	337	417	532	604	606	537	456	248	208	353	4409	26600	6.03	96.44%