Table 3. Impact of influenza-like illness and influenza on outpatient visits.

		No. outpatient	Excess outpatient visits	Excess percentage (%)	P value
2007~2009	ILI%	4056320	433947	10.7	0.049
	Positive rate	4056320	76417	1.88	0.042
2009	ILI%	1745899	296312	16.97	0.012
	Positive rate	1745899	36496	2.09	0.106
2008	ILI%	1266356	106526	8.41	0.179
	Positive rate	1266356	23145	1.83	0.223
2007	ILI%	1044065	104027	9.96	0.03
	Positive rate	1044065	11103	1.06	0.074

Note: ILI% is the percentage of the number of cases of influenza-like illness out of the total outpatient visits. The positive rate is the proportion of the number of influenza virus–positive specimens to the total number of detected specimens.