In 2015, for a National Statistics dataset to qualify, it must have a population census updated at least once a year.
I think only small countries may be able to conduct a national population census every year (or even the implied possibility of doing more than one census per year). The population census in Brazil is made by the National Institute of Geography and Statistic (IBGE) once every ten years. The last one has been in 2010. So, should National Statistics dataset be ruled out of the Open Data Index in all but the year a full census is actually performed? Or are future projections of population admissible for this dataset?