Fig. 3From: Seasonal Bordetella pertussis pattern in the period from 2008 to 2018 in GermanyAverage seasonal pattern of positive samples in each age group during 2008–2018 (proportions). The lines show the average proportion of positive samples with 95% confidence intervals in each age group for the months January to December in the study period. The bold line shows the median proportion of positive samples in each age groupBack to article page