I think its a tad disingenious to look at GDP without at least acknowledging the effects of the most sustained economic blockade in modern times, which let us not forget has also been instigated by the most powerful country in the planets history. Not only have they denied Cuba direct access to markets, but have wantonly encouarged their numerous accolytes to do similar. In addition to sanctions, they have also systematically been pro-actively aggressors, speculating against the price of sugar for decades, and even went so far as to 'design' a sugarbeat eating insect which they duly tried to infest Cuba with, before the Cubans worked out how to kill it.
Kennedy's "We will build a wall around Cuba" speech was delivered in March 1963 (why wasn't he watching Cheltenham?), which equates to over 40 years of semi isolation now. I'd be very surprised if there was another Carribean Island (other than the tax havens) that would be able to absorb that level and intensity of economic sanctions, (and quite a few more advanced countries on top of that who would seriously struggle under such punitive circumstances). Indeed I think the fact that what was essentially a third world Carribean Island having been subjected to this level of pariah treatment from the all powerful and hypocritical USA is still there today is a tremendous testimony and serves as a beacon to the region as to what could be achieved if any given society defined for themselves a new set of objectives. Why else would the Americans be so determind to maintain a cold war position which is obsolete today? what are their real motives now?
All of this leads me into an observation about how we account for a country's performance and the value we accord various measurements etc It does I think to a large extent reflect what you choose to value as a society, and how you prioritise by way of outputs than defines your sense of accomplishment. There are no shortage of countries enjoying a so called economic miracle whilst their people live in sacks. Also there has to be a sense of context when assessing Cuba in particular, given the unique circumstances they operate under, and that as a society they have structured against a different benchmark in accounting for this.
Therefore I also had to dip into the UN for the figures (not the sort of thing you bring to mind from memory no matter how many times you've heard the arguments for and against). The table combines GDP with a Human Development Index (essentially a handicap rating against spend and income from a regional report for the Carribean rim area). I think ultimately context is all important
0 = average + = positive - = negative. The precise methodolgy is explained in the full report, the only discrepancies concern different countries accounting periods, and those who express their wealth in USD's
Cuba +35
Suriname +29
Belieze +24
Panama +18
Jamaica +18
Dominica +16
Saint Lucia +15
Coasta Rica +14
Venezula +10
Martinque +9
Guadleloupe +9
Tinidad & Tobago +6
Barbados +5 (should imagine M. Stoute accounts for about a quarter of the GDP alone)
Bahamas +4
Nicaragua +4
French Guiana +2
Mexico +1
Haiti -2
St Kitts & Nevis -3
Guyana -4
Antigua -5
St Vincent -8
Barbuda -9
El Salvador -13
Guatamala -19
Domincan Republic -20
Grenada -22