Feature request: Allow line graphs instead of stacked area graphs

For some of the graphs, they would make more sense to use lines instead of stacked areas to display the data. For instance, on the mysql connections, a glance at the graph gives the impression that there are 3,400 connections in use, yet the max is 1,600. If this was a line graph, it would be much easier to interpret.

Would it be possible to add a switch or check box to switch to line graphs?