In Market Insights, you can choose between the 'Yearly-YTD' or the 'Yearly-Full Year' time period.

When you choose 'Yearly-YTD' what you're actually choosing is a 'Year to Date' calculation.  The chart will then include all listings grouped by year, from the beginning of each year through the current month of each year.  Refer to the definition at the top of the chart for the actual months included.  So if it's May 15th and you've been looking at stats for the month of April, the chart will display results for the months of January through April for each year.  The metric at the top will show you the YTD values for the current year, and the comparison month by default is the prior YTD value.

When you choose 'Yearly-Full Year', each year on the chart, except for the current year, will display the results for the entire year.  The current year will continue display the YTD value, as the chart does not annualize or project the metrics forward.

You may be thinking "doesn't this mean that the current year metric will always have the same value whether I choose YTD or Full Year?"  The answer is Yes, it will.  Even though it's not necessarily a 'fair' comparison to show prior full years vs the current partial year, it does show how the current year is tracking against prior years.  And then once December stats go live, you have true full year comparisons.  By exposing this time period, you also have the ability to go back and compare any prior year vs any other year prior to that.

So which time period is better to use?  The answer really depends on the type of metric you're reviewing.  For Counting metrics (Number of Closed Sales, Number of New Listing, etc.), YTD tends to be a better measure.  That's because those metrics are very seasonal.  Sales go up each summer and down each winter.  But for metrics that aren't seasonal, like Median Price or Percent Distressed, it's better to review those on an Full Year basis.