Graph construction help needed

Hi,

I would like to make a graph that shows which variable is considered over time. I have attached a picture of an example on how it could look as well as the file I'm working with.

In Excel the input I have is:

Time PSSL (Variables)
00:01 A
00:05 Cp
00:10 A
00:22 Cp
00:32 Cp
00:41 P
00:56 L
01:14 L
01:25

Looking at the example the A could correpond to 1, Cp to 2 etc.

Thanks!

/Svante