Received: 20 August 2019
Accepted: 8 January 2020
First Online: 23 January 2020
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: Secondary data were used for this study. In obtaining the micro data, a request was made on the National Bureau of Statistics website and approval was granted to download the data; hence, there were no ethical issues of concern. These data are public and freely available to anyone from National Bureau of Statistics on request. The website for NBS isExternalRef removed