Table 2 The Classification of Korean Articles by Publication Year

Publication Year	Frequency (%)
1970≤ <1980	3 (3.6%)
1980≤ <1990	25 (30.1%)
1990≤ <2000	9 (10.8%)
2000≤ <2010	26 (31.3%)
2010≤ <2017	20 (24.0%)
Total	83 (100.0%)