Table 2.

Incidence densities of IA

Year	# of cases (proven and probable)	# of patient days	incidence density (per 100,000 patient days)	95% CI	p-value (vs. 2003)
2003	32	391.445	24	5.59; 11.54	-
2004	16	407.007	15	2.25; 6.38	0.008
2005	15	407.644	6	2.06; 6.07	0.427
2006	7	415.980	5	0.68; 3.47	0.044
2007	11	431.954	4	1.27; 4.56	0.804