Sub sommemoyenne()
Dim somme As Double, plage As Range, ligne As Long
somme = 0
Worksheets(1).[$A$1:$BE$65000].AutoFilter Field:=2, Operator:= _
xlFilterValues, Criteria1:="=*Saint Jean*"
Set MaPlage = Worksheets(1).UsedRange.SpecialCells(xlCellTypeVisible)
For ligne = 2 To Range("b" & Rows.Count).End(xlUp).Row
somme = somme + Worksheets(1).Cells(ligne, 6).Value
Next
Worksheets(2).Cells(13, 7).Value = somme / Range("$A$2:$a$27").SpecialCells(xlCellTypeVisible).Count
End Sub