Conditionally remove duplicates

Anonymous here is the example power query script which you can use to achieve it.

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlTSUTI0ABFA7BZpaKYUq4MkaoRP1BxV1BhZFKTECCRqgmwCXNQUqyh2E/Cai12tBVa1lljdABSNBQA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [Emp = _t, Planned = _t, Hours = _t, Year = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Emp", Int64.Type}, {"Planned", Int64.Type}, {"Hours", Int64.Type}, {"Year", type text}}),
    #"Grouped Rows" = Table.Group(#"Changed Type", {"Emp", "Year"}, {{"Rank", each Table.AddIndexColumn(_, "Rank", 1)}}),
    #"Expanded Rank" = Table.ExpandTableColumn(#"Grouped Rows", "Rank", {"Hours", "Planned", "Rank"}, {"Hours", "Planned", "Rank.1"}),
    #"Added Custom" = Table.AddColumn(#"Expanded Rank", "New Planned", each (if [Rank.1] = 1 then [Planned] else null), type number),
    #"Removed Columns" = Table.RemoveColumns(#"Added Custom",{"Planned", "Rank.1"}),
    #"Changed Type1" = Table.TransformColumnTypes(#"Removed Columns",{{"Hours", Int64.Type}})
in
    #"Changed Type1"