Beginner question on data transformation

Hi denkersmahlzeit 

1) Yes, you must do it. Otherwise, it wouldn't work.

2) I'm not sure if you will be able to achieve everything through Power Query, but almost everything.

3) It's difficult the part of getting the values through years in the way it seems to be structured, but I will do:
(In excel will fill all the row with the year)
- Transpose the table

- Fill down the column 1 to get the nationality

- Promote headers

-Unpivot columns

- Fix the values by: duplicating Atributte comparing with a conditional value to get the year per row, fill again, filter "extra rows" that I don't need, rewrite the attribute by extracting value before delimter and then removing extra columns.

But that's my approach. Maybe there is something that doesn't work.

My "dummie" data is the following:

And my advanced editor code:

let
    Origen = Excel.Workbook(File.Contents("C:\Users\Equipo2\Downloads\ex.xlsx"), null, true),
    Hoja1_Sheet = Origen{[Item="Hoja3",Kind="Sheet"]}[Data],
    #"Tabla transpuesta" = Table.Transpose(Hoja1_Sheet),
    #"Rellenar hacia abajo" = Table.FillDown(#"Tabla transpuesta",{"Column1"}),
    #"Encabezados promovidos" = Table.PromoteHeaders(#"Rellenar hacia abajo", [PromoteAllScalars=true]),
    #"Tipo cambiado" = Table.TransformColumnTypes(#"Encabezados promovidos",{{"Semester", type text}, {"Hoschulen", type text}, {"1989", Int64.Type}, {"HS1240", Int64.Type}, {"HS1241", Int64.Type}, {"HS1242", Int64.Type}, {"HS1243", Int64.Type}, {"HS1244", Int64.Type}, {"1990", Int64.Type}, {"HS1240_1", Int64.Type}, {"HS1241_2", Int64.Type}, {"HS1242_3", Int64.Type}, {"HS1243_4", Int64.Type}, {"HS1244_5", Int64.Type}}),
    #"Columnas con nombre cambiado" = Table.RenameColumns(#"Tipo cambiado",{{"1989", "Year"}}),
    #"Columna de anulación de dinamización" = Table.UnpivotOtherColumns(#"Columnas con nombre cambiado", {"Semester", "Hoschulen"}, "Atributo", "Valor"),
    #"Columna duplicada" = Table.DuplicateColumn(#"Columna de anulación de dinamización", "Atributo", "Atributo - Copia"),
    #"Tipo cambiado1" = Table.TransformColumnTypes(#"Columna duplicada",{{"Valor", type text}}),
    #"Columna condicional agregada" = Table.AddColumn(#"Tipo cambiado1", "Personalizado", each if [#"Atributo - Copia"] = "Year" then [Valor] else if [#"Atributo - Copia"] = [Valor] then [Valor] else null),
    #"Rellenar hacia abajo1" = Table.FillDown(#"Columna condicional agregada",{"Personalizado"}),
    #"Filas filtradas" = Table.SelectRows(#"Rellenar hacia abajo1", each ([#"Atributo - Copia"] <> "1990" and [#"Atributo - Copia"] <> "Year")),
    #"Texto extraído antes del delimitador" = Table.TransformColumns(#"Filas filtradas", {{"Atributo - Copia", each Text.BeforeDelimiter(_, "_"), type text}}),
    #"Columnas quitadas" = Table.RemoveColumns(#"Texto extraído antes del delimitador",{"Atributo"}),
    #"Columnas con nombre cambiado1" = Table.RenameColumns(#"Columnas quitadas",{{"Atributo - Copia", "Universitat"}, {"Valor", "Total"}})
in
    #"Columnas con nombre cambiado1"