Figure 3
Number of cases per week between 1986 and 2008 in Niger (a) and seasonal cycle box plot of incidence (cases/100,000) by week for 38 districts in Niger from 1986 through 2008 (b). (b) each box shows the range in which the central 50% of the data fall. The box borders show the first and third quartiles and the crossbar shows the median. Values (outliers) exceeding the quartile values by more than factor of 1.5, the interquartile distance, are marked as crosses.