1000 kg. CO2 emissions per year per capita for various countries (source: Wikipedia).
Flot supports selections through the selection plugin. You can enable rectangular selection or one-dimensional selection if the user should only be able to select on one axis. Try left-click and drag on the plot above where selection on the x axis is enabled.
The plot command returns a plot object you can use to control the selection. Click the buttons below.
Selections are really useful for zooming. Just replot the chart with min and max values for the axes set to the values in the "plotselected" event triggered. Enable the checkbox below and select a region again.