I have a line chart as the picture below. The max and min values in my data are 410 and 290 for the peakflow series (the chart's visible range is something like 0 and 500 which is a bit pointless as there is no data below 290 or above 410). There are no zero values but there are empty values in the peakflow data.
Is there a way to define the chart's max and min values for the peakflow (left) vertical series?