Increase lcoationRate from 0 to 1.
Increase itemWidth from 0.1 to 1.2.
Set the width of X-axis categories differently.
In the example above, clusterWidth of Female series has been set as 2, and clusterWidth of Male series has been set as a default value of 1. clusterWidth is a relative value of the width of each series item in one category.
Increase clusterWidth of Female series from 0.1 to 2.0.