1. Ortiz-Ospina, E., and Roser, M. (2021). Global health. [online] Our World in Data. Available at: https://ourworldindata.org/health-meta [Accessed 25 April 2021].
2. Roser, M., Ortiz-Ospina, E., and Ritchie, H. (2021). Life expectancy. [online] Our World in Data. Available at: https://ourworldindata.org/life-expectancy [Accessed 25 April 2021].
3. World Health Organization (2021). Medical doctors per 1,000 people. [online] Available at: https://ourworldindata.org/grapher/physicians-per-1000-people?tab=chart&country=~OWID_WRL [Accessed 23 April 2021].
4. Our World in Data (2021). Size of young, working-age, and elderly populations. [online] Available at: https://ourworldindata.org/grapher/size-of-young-working-elderly-populations?country=~OWID_WRL [Accessed 25 April 2021].
5. Our World in Data (2021). The world population is changing: for the first time, there are more people over 64 than children younger than 5. [online] Available at: https://ourworldindata.org/population-aged-65-outnumber-children [Accessed 23 April 2021].