Hello,
this can only be done with a helper series. With your second chart screenshot, add a data series whose Y values are all 0 and the X values are 5000, 6000, etc. Remove the X axis labels, tick marks and grid lines. Make the data marker of the new series a
- sign, so it sits on the X axis and looks like a tick mark. Add data labels for the value below the marker. Add error bars to emulate the vertical grid lines.
Here is a screenshot with values that are not just 2 but 50 ticks off the full 1000 grid. Vertical grid lines are error bars, not chart grid lines.