主题：此统计错在哪里？

Dim Values() As String = {"语文","数学","英语","物理","政治","历史","地理","生物","总分"}
For Each Value as string in Values
dim tj as string = "[" & value & "排名" & "]"

For Each dr as DataRow in DataTables( value & "层次").DataRows
dim tt as Integer = DataTables( value & "层次").DataRows.count*0.2

dr("参考人数") = DataTables("八年级").Compute("count(单位)", "[单位] = '" & dr("单位") & "'")
dr("平均分") = DataTables("八年级").Compute("Avg( " & value & ")", "[单位] = '" & dr("单位") & "'")
dr("最高分") = DataTables("八年级").Compute("Max( " & value & ")",  "[单位] = '" & dr("单位") & "'")
dr("前20人") = DataTables("八年级").Compute("count(单位)", "[单位] = '" & dr("单位") & "' and " & tj & " <= '" & tt & "'")
next
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