Growth of Perm Route Starts Nationally (and some States)

The chart below shows the number of RUSA perm "Group Starts"(*) by year, the number of states in which those perms and perm-pops started, the number of perm "groups" by year for the six states with the most perm starts, and the number of perm "groups" for the other states not specifically shown.  [You might wonder why I decided to show six specific states:  (1) because that's the number of states that allowed the exhibit to fit on the page, and (2) there was rather a natural break-point in the counts between the sixth and seventh states.]

You will notice that the total number of "group starts" increased every year until 2016, when there were approximately 440 fewer start groups than in 2015.  I have a good idea why the count for North Carolina (NC) decreased by approx 130, being almost entirely due to two frequent riders being knocked off the road and their corralling of others to ride once or twice a week going missing, combined with two other frequent riders essentially retiring or at least taking a hiatus.   However, I have no information or knowledge about why California (CA) and Washington (WA) also showed significant decreases in their counts.  Guesses would include a post-PBP effect and perhaps a decrease in K-Hounds in those states.

I'm attempting no profound insights (at this time); just simply showing the high-level information.

I have not attempted to look at the amount of brevet riding by year / region or state.
 

Year	Groups	# States		CA	WA	TX	NC	FL	MD		others
2004	34	5		6	0	22	0	0	0		6
2005	124	9		10	21	57	0	0	0		36
2006	370	17		25	80	130	7	9	1		118
2007	764	23		182	101	248	22	29	24		158
2008	1,065	28		245	161	198	33	93	43		292
2009	1,815	31		353	332	395	45	114	56		520
2010	2,631	38		449	472	555	194	75	89		797
2011	3,921	35		724	569	663	349	93	168		1,355
2012	5,123	46		997	660	742	382	224	266		1,852
2013	5,175	47		1,048	803	555	392	215	278		1,884
2014	6,227	47		1,481	904	578	422	286	370		2,186
2015	6,803	48		1,484	1,125	511	449	339	323		2,572
2016	6,359	51		1,315	964	616	318	385	312		2,449
Total	40,411			8,319	6,192	5,270	2,613	1,862	1,930		14,225

(*) "Group Starts" -- for purposes of this chart / blog-post, a "Group Start" is one group starting one perm or perm-pop route (presumably at the same time, though I cannot confirm that same start time assumption), regardless of how big or small the group.

The 40-plus-thousand "group starts" in the above chart translate to approximately 68-thousand individual completed rides / "RUSA-T" certificates.  [Obviously, there is a lot of solo riding occurring on perms.  Hey, I like doing solo bike rides, but it is rather amazing the amount of solo rando perm riding that occurs.]