Price increases are more common in the last ~3-4 years. Previously they were quite far apart; years apart, and even some price decreases - one decrease for most items, and some select price decreases for a few lines at a time just within the last 7-8 years), so for the past 3-4 years I do not see a pattern as of yet. It seems around Christmas time/New Year and/or around Summer there have been increases more often than not in the last couple of years, but the increases have become acutely so much more frequent that it is really hard to tell if it is by chance or design.