Grey Army versus the commuters on the SMBI

Just judging by the numbers on the
ferries is a poor guide 

If we have a common myth on the islands, it is that the islands is becoming more of a commuter community than the retirees.
The reverse is true.
Below is a comparison using the Census figures of 2011 and those of a decade ago.  While the overall numbers have increased by nearly double  to 5,626 the number of older people either retired or close to setting up for retirement is increasing faster than the other groups. The proportion of workers 50 to 59 approaching retirement has fallen from 22.8% to 16.3%. parents and home builders in the 35 to 49 age group has fallen from 18.6% to 17.3%  and the young workforce in the 25 to 34 bracket have remained constant, those in the 60 to 84 group have dramatically increased.
Most telling of these groups is the jump in the retiree and empty nester group aged from 60 to 69 who have gone from being only 7.3% of the population to nearly a quarter at 23.1.
In theory such a large proportion of retirees should indicated a higher degree of voluntary work making up for the gaps in the social services available on the islands but it doesn't: the numbers are only slightly above those of Redland City as a whole and, ominously, the 18.4% participation is falling fast from the 21% we had  in 2006.
The question is will, granted these trends, inclusion of the SMBI in Translink  help or hinder the sustainability of the islands?

Southern Moreton Bay Islands	2011			2001			Change
Service age group (years)	Number	%	Redland City %	Number	%	Redland City %	2001 to 2011
Babies and pre-schoolers (0 to 4)	335	6	6.2	146	4.5	6.6	189
Primary schoolers (5 to 11)	387	6.9	9.5	239	7.3	11	148
Secondary schoolers (12 to 17)	346	6.2	8.9	181	5.6	9.8	165
Tertiary education & independence (18 to 24)	216	3.8	8.7	103	3.2	8.7	113
Young workforce (25 to 34)	386	6.9	10.6	225	6.9	11.9	161
Parents and homebuilders (35 to 49)	975	17.3	21.4	606	18.6	23.7	369
Older workers & pre-retirees (50 to 59)	919	16.3	14	742	22.8	12.7	177
Empty nesters and retirees (60 to 69)	1300	23.1	11	631	19.4	7.3	669
Seniors (70 to 84)	725	12.9	7.8	349	10.7	7	376
Frail aged (85 and over)	37	0.7	2	30	0.9	1.2	7