关于MVC和ECharts的一个问题

本人就是想让柱状图获取的是表内区间的全部数量，例如100-200之间有多少个，就是0-30   31-90  91-180  181-365  365以上，这5个。，这是要获取的表内容。

怎样才可以让这5个柱子分别代表0-30   31-90  91-180  181-365  365以上，的各个数量。现在的柱子是全部的。并没有区间。
底下是代码，求怎么改，

 public LineChartDataModel<int> GetUkeyChart()
        {
            using (var DbContext = new CRBFoundationDbContext())
            {
                var rankSize = 5;
                
                LineChartDataModel<int> lineChartDataModel = new LineChartDataModel<int>()
                {
                    SeriesData = new List<ChartSeries<int>>(),
                    XAxisData = new string[rankSize],
                    ExpandProp = new string[rankSize]
                };
                var list1 = DbContext.Database.SqlQuery<ST_UkeyPersonMain>("select * from ST_UkeyPersonMain where PersonID >0");
                var list = (
                 from t in
                     (
                         from o in list1
                         
                         select new { UnitName = o.DueDay}).ToList()
                 orderby t.UnitName
                 group t by new { UnitName = t.UnitName } into G
                 select new { UnitName = G.FirstOrDefault().UnitName, Count = G.Count() } into x
                 orderby x.Count descending
                 select x).ToList();
                int num = 0;
                if (list == null || 0 >= list.Count())
                {
                    ChartSeries<int> chartSeries = new ChartSeries<int>()
                    {
                        Data = new int[rankSize],
                        Name = string.Concat("UK排行Top", rankSize.ToString())
                    };
                    ChartSeries<int> chartSeries1 = chartSeries;
                    for (int i = 0; i < rankSize; i++)
                    {
                        chartSeries1.Data[num] = 0;
                        int num1 = num;
                        num = num1 + 1;
                        lineChartDataModel.ExpandProp[num1] = "";
                    }
                    lineChartDataModel.SeriesData.Add(chartSeries1);
                    return lineChartDataModel;
                }
                ChartSeries<int> chartSeries2 = new ChartSeries<int>()
                {
                    Data = new int[rankSize],
                    Name = string.Concat("UK排行排行Top", rankSize.ToString())
                };
                ChartSeries<int> count = chartSeries2;
                foreach (var variable in list.Take(rankSize))
                {
                    count.Data[num] = (int)variable.Count;
                    int num2 = num;
                    num = num2 + 1;
                    lineChartDataModel.ExpandProp[num2] = variable.UnitName.ToString();
                    lineChartDataModel.XAxisData[num2] = (num2 + 1).ToString();
                }
                lineChartDataModel.SeriesData.Add(count);
                return lineChartDataModel;
            }
        }

xAxis : [
        {
            type : "category",
            data : ["1月","2月","3月","4月","5月","6月","7月","8月","9月","10月","11月","12月"]
        }
    ]

xAxis : [
        {
            type : "category",
            data : ["0-30",‘31-90’....]
        }
    ]

source.Select(u=>{
if(u.xxx<=30)
return 0;
else if(u.xxx<=90)
return1;
//...
else
return n;
}).GroupBy(n=>n);