The labels are overlapping because they do not have enough space to fit in. To resolve this you can use the axis' StepLabelLevelCount or LabelRotationAngle properties. The StepLabelLevelCount defines the number of levels which will be used to distribute the axis' labels. The LabelRotationAngle controls the rotation angle of the labels. You can read more about the properties in the X-Axis
I hope this helps.
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