Problem with the data behind the border

Dear all.

I am wasting a lot of time trying to resolve a graphic problem. I would like a graph with the starting at (0,0), This can be done with the codes xaxs="i", yaxs="i". Then, the lowest values of each of my variables are drawn behind the axis, ruining the resulting graph as shown in this picture:
R%20Forum

Here is how I would like it

Is there a solution?

Thanks in advance!