Descriptive statistics of the antibody ELISA for 10 randomly selected samples per serum-dilution and serotype. Box-and-whisker diagram of the measured optical density percent (ODP) per dilution and serotype. Showing the smallest observation, lower quartile (Q1), median, upper quartile (Q3), and largest observation. In addition outliers according their interquartile range (IQR) and means are displayed. The top and bottom diamond vertices are the respective upper and lower 95% confidence limits (CI) about the group mean. Each circle represents the measured ODP of a sample. The red line represents the threshold for each serotype, i.e samples are considered negative if the ODP is for O >= 50, for A >= 45, for Asia 1 >= 35 and for C >= 35.