Description:
This graph shows a trellis line + symbol plot of internet usage, with two variables -- development index and year -- defining the panel structure.
By default, this arrangement would be plotted as a single row with six panels. However, we can set options to wrap the panel if columns/rows exceed 3 and by doing so, the graph becomes a 3*2 panel trellis plot. Further, we used combined grouping information to generate the panel title.