Figure 15: Rate of respiratory viral presentations to Western Australia emergency departments, 2008 to 2009, by week This figure presents the weekly rates of ILI presentations to Perth (WA) emergency departments between 2008 and 2009. Respiratory viral presentations to during 2009 began to increase in late May and peaked in early August. %. In comparison, the number of presentations observed in 2008 had a lower and later peak, and the duration above baseline activity was shorter.