Some UNOFFICIAL statistics based solely on my interpretation of data from this thread.
Teams entered the contest: 284 (may be a bit off as I didn’t manage to grab the most recent list before it was replaced with the list of finishing teams, still should be close enough)
Breakdown by members count:
Teams with just 1 member: 131
Teams with 2 members: 52
Teams with 3 members: 32
Teams with 4 members: 28
Teams with 5 members: 41
That makes 4 members per team the least common and 1 members per team the most common, seconded by 2 members per team.
Now to the finishing teams. Total number of teams that finished the contest is 190.
Breakdown by members count:
Finishing teams with just 1 member: 87
Finishing teams with 2 members: 29
Finishing teams with 3 members: 21
Finishing teams with 4 members: 21
Finishing teams with 5 members: 32
That gives us the following data: 67% of all teams have finished the contest.
66% of all 1 member teams have finished the contest which is pretty close to total percentage of finishing teams.
Just 55% of 2 members teams have finished, being by far the least effective member count.
66% of 3 members teams have finished the contest, also pretty close to average.
75% of 4 members teams have finished, which is significantly above average, also remember that 4 members per team was the least common team configuration among entering teams.
78% of 5 members teams have finished the contest, being by far the most effective team configuration.
is all the data in table form if you prefer that to my mumblings:
members entered finished % finished
1 131 87 0.6641221374
2 52 29 0.5576923077
3 32 21 0.65625
4 28 21 0.75
5 41 32 0.7804878049
total 284 190 0.6690140845
Now some interpretation by me, may be totally wrong. Apparently the more members you have in your team the better your chances to finish your project (who would have thought), except two members, you are far better off alone than with one other person. Probably it is because in two members team there is no apparent leader and has their own idea of things and there is no one to tip the scales to either side.
Teams with more members are probably more prepared and take things more seriously, after all the effort they took to put their teams together they wouldn’t want to just give up half way. Percentage of finishing 1 person teams is almost exactly the same as total percentage of finishing teams, so being alone is ok, but if you truly want to have an advantage then grab some extra manpower. Also those numbers should probably be weighted because there are much more 1 member teams than any other member count so all of the above may not mean anything.