Thanks. I guess the increased applications will probably pollute the data enough to make it impossible to find evidence (if it exists) of seasonal effect.

I had hoped one could perhaps see the effect of something like Subsyndromal Seasonal Affective Disorder (affects ±14% of population) or Seasonal Affective Disorder (http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002499/).