Fig. 1

The KL difference (°) for males and females versus age (years). The thick horizontal line at the pinch point represents the median value with the box surrounding that, the interquartile range. The solid dark blue dot and associated bars represent the mean and 95% confidence interval for the mean. The dotted line and whiskers are up to 1.5 times the interquartile range and any data beyond that is seen as an open circle