I made a pass going through and cleaning up this summary data from how many teams drop out, how many come back, etc.
I liked Chris's approach to charting that data, so I've done the same with some variation.
I correlated team lists from 1992 onwards (early years from the Team 45 TechnoKats
history project) and treated the teams as returned if the same high school or equivalent was involved. There are cases of teams splitting off into different team numbers that I haven't decided how to account for, so right now a new team number is treated as a new team, even for those few teams that just had their number changed for unknown reasons from one year to the next, e.g., Bay Shore HS in
1998, and
1999.
I also haven't walked the early teams all the way up to the present to catch those that returned 10 years later.
I'm hopeful we'll soon have the full spreadsheets posted on our website for others (all eight of you
) to play with, use, and improve upon.
P.S.
You'll see that the total teams for several years are one or two off from FIRST's published totals. I decided to use totals supported by corresponding team lists to avoid counting teams that dropped out before actually competing. Some of FIRST's team totals appear to be propagated from tally's taken before team registration settled out, e.g., for 2009 FIRST listed 1686 teams because the count was from early January, but only 1677 teams were around for actual competition.
I also plan to update the pre-1998 team rookie year's. The current one's listed for the early year's are incomplete, possibly because FIRST had different early rules that defined when a team was "new." I'm just going to go by if the same educational institution (or equivalent) was involved. Originally FIRST identified teams and team continuity by the corporation or business that sponsored them, so my approach will yield different results for the 1990's.