“…One was an inquiry relating to family annual income as reported in our previous study (Taki et al, 2010;Takeuchi et al, 2014). Annual income data were collected using discrete variables: 1, annual income ϽUS $20,000 (the currency exchange rate was set at US $1 ϭ 100 yen); 2, annual income US $20,000 -$40,000; 3, annual income US $40,000 -$60,000; 4, annual income US $60,000 -$80,000; 5, annual income US $80,000 -$100,000; 6, annual income US $100,000 -$120,000; 7, annual income ՆUS $120,000.…”