Table 3. Yearly relative risk for introduction of low pathogenicity avian influenza virus in indoor-layer farms, the Netherlands.

Year	Relative risk (95% CI)
2007	1 (reference)
2008	0.65 (0.48–1.04)
2009	0.63 (0.28–0.84)
2010	0.41 (0.28–0.68)
2011	0.56 (0.44–0.70)
2012	0.5 (0.30–0.83)
2013	0.15 (0.04–0.27)