Population by age - mid-year estimate
Mid-year estimation provided by StatsSA. According to the publication: "Mid-year population estimates uses the latest available data on fertility, mortality and migration to estimate the size of the population of South Africa. "
Get the following document:
District Council projection by sex and age (2002-2018) (478,47 KB)
Locate Cape Town in here. Then sum all the categories to get the total population, broken down by age. Lots of transposing of data.
Download the original data in CSV format using the link below.