RUSA Retention -- Some Data

Occasionally (meaning not so often that I can use the adjective "periodically"), my friend Bob will mention concerns regarding the retention of new RUSA members.  For example, of the 34 North Carolinians that first joined RUSA in 2010 (which is when Bob and I joined RUSA), only 10 appear to still be active. 

What is the usual retention rate of new RUSA members?
And ... there is a whole series of questions that can open up after that initial question;
However, I won't attempt to list them ... now.
Because the first thing to do is find some data that would address the initial question:
What is the usual retention rate of new RUSA members?

I'm informed that the RUSA database may have the date when an individual first joined RUSA.
However, I don't have access to the database.
Luckily, one doesn't really need to access the database to get some good data on retention, 
Because on the RUSA website, in the RBA resources section, there are Excel compatible files
That include all RUSA members by RUSA number, and
Indicates their last renewal date (which I typically refer to below as "termination date").

A comment on "last renewal date" --
I understand that RUSA does not track intermittent membership dates--
Some stop being members for awhile, return, leave, return, rinse, repeat.
Tracking that would require a lot more effort and resources
Than is needed to answer the question that RBAs and Perm-route-owners need to know:
Namely, "is the person currently a member?"
(Since the intermittent information is not needed, there is no need to retain it.) 

The information in the aforementioned files does NOT include the date when someone first joined RUSA.
However, one's RUSA number is a decent substitute.
At least I assert that it will suffice for looking at longitudinal retention rates. 

Okay, enough with the gibberish.
Here is a chart, organized by 1000-cohorts,
Showing the distribution of termination dates within each cohort.
 

	RUSA #s -- Termination date within "1000 number" cohorts
											Total
Term Date	1	1000	2000	3000	4000	5000	6000	7000	8000	9000	Term'd
12/31/1999	211										211	PBP year
12/31/2000	71	13									84
12/31/2001	31	54									85
12/31/2002	35	92	1								128
12/31/2003	89	225	132								446	PBP year
12/31/2004	26	82	135			1					244
12/31/2005	21	36	151	40							248
12/31/2006	27	35	62	143							267
12/31/2007	74	85	102	223	264						748	PBP year
12/31/2008	33	28	42	89	197	48					437
12/31/2009	28	31	36	76	85	218					474
12/31/2010	22	26	26	45	68	171	146				504
12/31/2011	43	46	43	54	62	85	297	41			671	PBP year
12/31/2012	37	44	48	53	50	110	138	407	14		901
12/31/2013	149	115	147	162	182	227	276	401	785		2,444
12/31/2014	49	49	54	67	53	95	98	119	130	103	817
12/31/2015	44	31	17	36	33	40	37	30	64	11	343	PBP year
12/31/2016	3	6	2	7	6	5	8	2	6	7	52
12/31/2017	0	0	0	0	0	0	0	0	0	0	0
beyond	0	0	0	1	0	0	0	0	1	0	2
total	993	998	998	996	1,000	1,000	1,000	1,000	1,000	121	9,106
active	245	201	220	273	274	367	419	552	986	121	3,658

• Note that the above data was obtained from the RUSA website on Nov-13-2013. 
• I expect that approx 2/3 of the members currently shown with a termination date of 2013 will renew their memberships (most before the end of the year). 
• You may notice that there are 15 member numbers missing from the first 4000. I don't know why, but some numbers were either skipped, or perhaps provisionally issued and then reversed.  I have not attempted to learn the specifics.  Those situations have a negligible impact on the data (and any subsequent analysis). 
• You may notice that one person in the 5000-5999 cohort is shown as having a last terminated date prior to when that RUSA number would have been issued.  That actually gives me some comfort -- any database worth its salt ought to have an error or two embedded in it somewhere. 

 
It is my intention to limit this post to the publication of the data.
Any subsequent "analysis" will come in later posts.

If you have any analysis-type questions that come to your mind when you see the above,
Please leave a comment with said question.