Out of interest I have carried out a comparison of members v Countries as per current Committee. Of course it could be said that a comparison by Area or Population might be fairer - but UNESCO generally works on a "All countries are equal" basis so I stuck with that.
We know of course that UNESCO "Regions" are to some extent "fabrications" but I was surprised to discover that "Malta" is said by the UNESCO Web site "Region pages" to be in BOTH Europe AND Arab States! See http://www.unesco.org/new/en/unesco/worldwide/arab-states/
Whilst there are examples in some parts of UN's organisations where States are assigned to 2 regions (E.g Turkey), I have taken this to be a mistake and treated it as European since this UNESCO page on Arab Region statistics doesn't include it http://www.uis.unesco.org/DataCentre/Pages/regions.aspx
There are also "Associate members" in some regions. I have given their numbers in brackets but have excluded them from the %age calculations.
So Region, Number of Full Member States, (Plus number of Assoc States), Number of WHC Members, %age of full member states in the Region which are on WHC
Africa, 54, (0), 4 = 1.85%
Arab St, 21, (0), 3 = 14.28%
AS/Pac, 48, (2), 6 = 10.41%
Eur/NAm, 52, (1), 6 = 11.53%
Lat Am/Car, 33, (7), 3 = 9.09%
So Europe, Latin America and Asia Pacific are all around 10%. The 2 exceptions are Arab States which appear to be heavily over represented at 14.28% and Africa which appears to be the converse at 1.58%. HOWEVER - I note that the 8 States situated on the African continent geographically which have been included in the Arab region are ALSO included in the count of 54 States of the African region on the UNESCO web page (Som, Dji, Alg, Sud, Egy, Liby, Mauritan - of which Tunisia is on the WHC and has been included by me in the Arab line above for WHC members). To avoid this double counting we either have to remove all African Arab states from Africa OR remove all non African Arab states from the Arab list (and in this case add 1 to the African total of WHC members for Tunisia)
a. Remove All Arab African states from Africa
Arab States (inc those in Af), 21, (0), 3 = 14.28% (ie no change as above)
Africa (less Arab states), 46, (0), 4 = 8.70% (I.e increased from above by removing 8 states from the %age calc)
b. Remove all Arab African states from Arab Region
Arab States (less those in Africa), 13, (0), 2 = 15.38% (i.e decreased from above by removing the African states and the WHC count for Tun)
Africa (inc Arab states in Af), 54, (0), 5 = 9.26% (I.e Increased from above by adding Tunisia's membership of WHC)
In either case one must conclude that
a. Africa is under represented
b. Arab states are over represented.
However if we add the 2 regions together to give a single Afro/Arab grouping we get
Afro Arab, 67, (0), 7 = 10.44%
This is remarkably similar to the %ges of the other 3 regions!! And, indeed, this seems quite reasonable given that those states sitting culturally and "emotionally" on both the Arab AND African region can (and do!) operate together for the benefit of each region. We can probably expect to see more examples of the slightest hint of over zealousness (or even less!) in the treatment of nominations from either region being down voted - especially as some European and Asian states don't seem willing to stand up and be counted - an acquiescence in a "Deferral" is the "easiest" option!