Here's more data! (since you can never have too much data)
Instead of just looking at OPR rank, I graphed it according to standard deviations above above the mean. 254 once again dominates, with several records: the only team with an average above 4, 1 of 4 teams to break 4 in a single year, 1 of 2 teams to break 4 in both categories (max/avg OPR), and the only team to break 5 (and even 6 in avg OPR).
Each category includes the 10 teams with the highest average (not highest rank as previously used). For the average, I used only CA teams, and the relevant stats (i.e. for max OPR, the average was the average of all max OPRs)
I think this is somewhat more representative than just rank (since it adjusts for how far above average you are), but it does make the graphs messier:
The top team per year in CA (standard deviations above average, max OPR, (CA data set only) (all teams)):
2012: 1717 (4.51) (4.77)
2013: 1538 (3.97) (4.71)
2014: 254 (4.01) (3.52)
2015: 254 (5.86) (6.57)
2016: 971 (4.06) (4.15)
Top teams in the world (data set now includes all teams):
2012: 2056 (5.20)
2013: 987 (4.93)
2014: 1114 (4.21)
2015: 254 (6.57)
2016: 148 (4.35)
Teams for 2008 to 2011 are 1114, 71, 67, and 111, which gives Ontario a third of the top spots in the past 9 years.