Verified	Status	Citation	Memento
2021.05.18	a	https://www.census.gov/content/dam/Census/library/visualizations/time-series/demo/families-and-households/hh-4.pdf
2021.05.17	a	https://ourworldindata.org/living-alone
2021.05.17	a	https://www.self.inc/blog/adults-living-alone