Figure 5 is a line graph showing the national proportion of participants with ILI (defined as fever and cough) compared with counts of national influenza laboratory notifications for each week ending Sunday from 2009 to 2012. A similar seasonality pattern is seen in both the Flutracking ILI data and confirmed influenza notifications, with Flutracking ILI activity peaking up to four weeks earlier than confirmed influenza notfications in all years, except 2011 where confirmed influenza notifications peaked one week earlier than Flutracking ILI activity. There was an increase in the number of laboratory confirmed cases of influenza between 2010 and 2012 (from 1,301 in the peak week of 2010 to 2,026 in the peak week of 2011 to 3,631 in the peak week of 2012). The peak weekly ILI activity for 2012 Flutracking data was also higher (4.7%) than the peak weekly prevalence for 2011 (3.8%) and 2010 (3.7%). However, the increase in Flutracking ILI activity was not as large between 2010 and 2011 as it was for laboratory confirmed cases of influenza.