Cache Size Evolution

The first chart is the most meaningful.  It shows the change clearly.  The chart that distinguishes between caches labeled small vs micro has the following problems.
  1. The small cache designation wasn't adopted until somewhere in 2005 or later.  Before that most people called them micros.  The earlier data showing smalls before that must have been people who relabeled older caches from micro to small once that designation became available.  For example, a person could have placed and labeled a cache micro in 2003 and later changed it to small when that designation became available.  My data counts the cache the year it was placed and can't know if the size was changed later.
  2. My observation is there's been size creep over time.  Some new cachers are labeling caches small that in prior years would have been labeled micros.  I've imagined this may partly be because newer cachers have seen so many of the tiny containers (nanos, Bison tubes, etc.), which didn't use to exist, to them a large pill bottle seems like it must be a small.  (My rule for a small is it must have the volume of a tennis ball.)
  3. My intent was to show the decline of regular (they were called regular for a reason) caches and the chart separating smalls from micros muddies that. 

I omitted 2001 & 2002 because my data's bad back then and geocaching had growing pains with some odd things going on.  For what it's worth in 2001 (the first year of caching) 96% were regular caches and 4% micros in my iffy data. 

Percent of Caches by Size Over Time