eight-square
7.For the year subject to the assessment, we take eight basic indices of seismicity data of the past three years,the conversion number of earthquake N and the absolution of the error between two continue years |△N| ,the earthquake energy E and their |△E| ,the number of square degree of earthquake distribution n and their |△n| ,the average distance between the centers of square degrees τ and their |△τ|.

