This is my chart:

Different colours mean different years, it is for student application (for example, for Year 2015, my application can start as early as 2013) --- what should I do if I want to compare them from the same starting month? The difficulty is that normally each line lasts for more than a year -- so I cannot compare just from Jan to Dec for the 3 years --

ideally, want I want to do is the set up a starting month as Month 1 when the Year gets a figure (so maybe I have Month 1 to Month 23 for Year A/B/C)