Summary 8-12 May
The graph reflects the trend by showing the percentages of on time, late or very late/cancelled trains at the end of the week. I've chosen to show the prior six weeks, as week-by-week cannot really show a trend - it's too variable, especially if I'm going to Perth more often (I tend to be lately). This is pretty arbitrary, but it feels about right to me.
So the cumulative stats show that we still have 61% on time, 23% a little late and 16% very late or cancelled. The trend shows a positive peak in November, dropping quickly into January then steadily climbing again until fairly recently. Reliability seems to have been declining a little since.
While we're on the subject of reliability, it seems Mr Bracks is about to pay somebody $5,000,000 to find the solution to Melbourne's traffic congestion. Tell you what Bracksie, give me 10% of that and I'll give you the answer... FIX OUR PUBLIC TRANSPORT!