Granma, the official newspaper of the Communist Party of Cuba, published an article about projections of Cuba’s population by the island’s National Bureau of Statistics and Information.
Here is an attempt to put that article’s textual account and the Bureau’s tables into the following table of millions of Cubans (no available information for empty cells):
While the total and economically active population over the next 15 years are projected to stabilize around 11.3 million and 5 million respectively, the number of people over 60 years of age is projected to increase from roughly 2 to 3 million. This obviously will present problems and issues of financing the care of the elderly.
It is also unclear whether the Bureau has attempted to evaluate whether and to what extent there will be net out-migration of Cubans to the United States and elsewhere in search of better economic opportunities. Such calculations would be difficult under any circumstances, especially with the overhanging issue of whether and when the U.S. would eliminate its special immigration benefits for Cubans.
 Curbelo, Projections on the Cuban population, Granma (Sept. 5, 2016); ONEI, Anuario Estadístico de Cuba Población 2015 (Edición 2016); ONEI, Projections of Economically Active Population, 2015-2030.