39 When we look at the distribution of survey respondents regarding year of birth (cf. <Table 3-4>), persons born in the 70s make up almost half of the sample (42.9%), while those born in the 60s and 80s make up 25.3% and 24% respectively, comprising the other half. <Table 3-4> Distribution of survey respondents with regard to year of birth Year of birth Number of persons Percentage (%) 1940s 4 1.6 1950s 11 4.0 1960s 63 25.3 1970s 107 42.9 1980s 60 24.0 1990s 2 0.8 Sum 247 99.6 No answer 1 0.4 Total 248 100 <Table 3-5> Distribution of survey respondents by age group Age group Number of persons Percentage (%) Under 20 3 1.2 20s 53 21.4 30s 102 41.1 40s 70 28.2 50s 16 6.5 60s 4 1.6 Total 248 100.0 As confirmed by the age group distribution shown in <Table 3-5>, North Korean refugee women in their 30s constitute the largest age group in the sample; combined with those in their 20s and 40s, the stratum of young adults and middle-aged women make up 90.7%. This phenomenon can be thought to reflect the biological age at which something as dangerous as the process of flight from North Korea can be physically endured and achieved. Furthermore, women in their young adulthood and middleaged women constitute the socially most active stratum and are age groups which still