Figure 1
The flow chart of sample selection and follow-up. The response rate was 70.9% in 2011 to yield 8245 interviews and the response rate in 2015 was 76.8% to yield 4182 interviews.
The flow chart of sample selection and follow-up. The response rate was 70.9% in 2011 to yield 8245 interviews and the response rate in 2015 was 76.8% to yield 4182 interviews.
