Nifty Rollover vs. Next Month Return

Does Nifty Rollover cost (which may include dividends as well) have any relation to the kind of returns Nifty generates in the following month. Based on that thought, did a test on Nifty current month futures vs next month. All dates used as Last Thursday of the month.

Here are the results:

When premium was > 1.0 percent, the return in the following month was the lowest. The data is from 2000 till October 2013 and hence includes months in 2008 / 09 when we saw huge swings on either side. 

If I removed the big outliers (biggest gaining month and biggest losing month), the picture comes to show like this

While we can see the big negative bar missing, the positive does not change much showcasing that when Nifty runs in discount, the possibility of gains outweigh losses. Of course, this would be too simple a extrapolation and not useful for trade, but a thought all the same.