What country has the lowest percent of families who are homeless or living in poor quality houses?

Japan

Explanation:

The country with the smallest share of homeless people is Japan (0.004% of the population in 2019), where figures only refer to people sleeping rough, defined as “people who live their daily life in a park, a riverbed, at a road, a station or other institutions” (Ministry of Health, Labour and Welfare, 2019).