ABSTRACT
This research involves annual numerical data of 10 consecutive years, thus it had better to choose gray rational analysis which had not strict requirement for sample size and data distribution. Gray rational analysis is a way to analyze the correlation between factors in the same system by using the geometric relations between series that correspond to the factors. There are several kinds of gray rational analysis; general gray rational analysis is applied in this paper. The method is used to study the relations of absolute and relative increment of two series, the correlation of the two series is measured by the size of the area between two broken lines that represent the two series. General gray rational analysis includes gray absolute rational analysis, gray relative rational analysis and gray synthetic rational analysis (see, Liu Sifeng et al. 2010) cannot only reflect the degree of geometrical similarity of two series but also scale the close degree of the rate of change of two series, is a comprehensive analysis that reflects geometric relations between series.
