Spline graph less than 0

Hi when I use type spline on my chart, if value close to 0 or equal 0, than line on graph shows under the xAxis, how I can solve this ? ? for example, that the line was on 0 but not under 0.

I use scale (0-100%) on the Yaxis and when the line shows under 0 it looks impossible

this is data which used by chart on screenshot

var companies=[ { "companyA":"4.8", "companyB":"2.3", "month":"Jan" }, { "companyA":"5.0", "companyB":"12.1", "month":"Feb" }, { "companyA":"3.2", "companyB":"0.0", "month":"Mar" }, { "companyA":"3.1", "companyB":"0.0", "month":"Apr" }, { "companyA":"1.0", "companyB":"5.0", "month":"May" }, { "companyA":"1.3", "companyB":"2.6", "month":"Jun" }, { "companyA":"3.2", "companyB":"3.0", "month":"Jul" }, { "companyA":"2.3", "companyB":"5.0", "month":"Aug" }, { "companyA":"1.9", "companyB":"1.4", "month":"Sep" }, { "companyA":"2.2", "companyB":"1.0", "month":"Oct" }, { "companyA":"4.0", "companyB":"1.5", "month":"Nov" }, { "companyA":"6.0", "companyB":"4.0", "month":"Dec" } ];


The issue does not relate 0 value. Graph has correct shape and it will be almost the same with greater values.
In the next version graph will be limited by scale and draw a flat line in such a case.

The next version is planned for April.