Excel Challenge 70 – Brian Julius Solution

gistfile1.txt

let
    Source = Within20Raw,
    #"Sorted Rows" = Table.Sort(Source,{{"Champion", Order.Ascending}, {"Year", Order.Ascending}}),
    #"Added Index1" = Table.AddIndexColumn(#"Sorted Rows", "Index.1", 1, 1, Int64.Type),
    #"Added Index" = Table.AddIndexColumn(#"Added Index1", "Index", 0, 1, Int64.Type),
    #"Renamed Columns" = Table.RenameColumns(#"Added Index",{{"Index", "Index0"}, {"Index.1", "Index1"}}),
    #"Merged Queries" = Table.NestedJoin(#"Renamed Columns", {"Champion", "Index0"}, #"Renamed Columns", {"Champion", "Index1"}, "Renamed Columns", JoinKind.LeftOuter),
    #"Expanded Renamed Columns" = Table.ExpandTableColumn(#"Merged Queries", "Renamed Columns", {"Year", "Champion"}, {"Year.1", "Champion.1"}),
    #"Filled Up" = Table.FillUp(#"Expanded Renamed Columns",{"Champion.1"}),
    Valid = Table.SelectRows( #"Filled Up", each [Champion] = [Champion.1]),
    #"Changed Type" = Table.TransformColumnTypes(Valid, {{"Year", Int64.Type}, {"Year.1", Int64.Type}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "WIthin20", each if [Year.1] = null then "Y" else
if [Year] - [Year.1] <= 20 then "Y" else "N"),
    #"Grouped Rows" = Table.Group(#"Added Custom", {"Champion", "WIthin20"}, {{"Count", each Table.RowCount(_), Int64.Type}, {"All", each _, type table [Year=nullable number, Champion=nullable text, WIthin20=text]}}, GroupKind.Local),
    #"Added Custom1" = Table.AddColumn(#"Grouped Rows", "YearsUncorr", each [All][Year]),
    #"Extracted Values" = Table.TransformColumns(#"Added Custom1", {"YearsUncorr", each Text.Combine(List.Transform(_, Text.From), ", "), type text}),
    #"Filtered Rows" = Table.SelectRows(#"Extracted Values", each ([WIthin20] = "Y")),
    #"Added Custom2" = Table.AddColumn(#"Filtered Rows", "Prev", each [All][Year.1]),
    #"Extracted Values1" = Table.TransformColumns(#"Added Custom2", {"Prev", each Text.Combine(List.Transform(_, Text.From)), type text}),
    #"Added Custom3" = Table.AddColumn(#"Extracted Values1", "Years", each if [Count] = 1 then [Prev] &", " & [YearsUncorr] else [YearsUncorr]),
    #"Added Custom4" = Table.AddColumn(#"Added Custom3", "Sort", each Text.Middle( [Years], 0, 4)),
    #"Sorted Rows1" = Table.Sort(#"Added Custom4",{{"Sort", Order.Ascending}}),
    #"Removed Other Columns" = Table.SelectColumns(#"Sorted Rows1",{"Champion", "Years"})
in
    #"Removed Other Columns"