상관분석 결과 상관계수가 2등급 단계와 4등급 단계에서는 0.36, 4등급 단계와 6등급 단계에서는 0.70으로 분석되었다.
As a result of the correlation analysis, the correlation coefficient was analyzed as 0.36 in the 2nd and 4th rank stages, and 0.70 in the 4th and 6th rank stages.