United Nations report World Population Prospects: The 2008 Revision (highlights available here) provides data about the historical and forecasted population of the country. In exploring the future and past population trends it is relatively easy to subset the dataset by your selected variable.
> file <- c("UNdata_Population.csv")
> population <- read.csv(file)
> names(population) <- c("code", "country", "year",
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Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).