Extract Zone unique values

Hi Edgar, this is part of the csv file:

Casenr,Straat,Lat,Long,Waarde,Value
1,Kaminda George Willems,12.1529341,-68.8739812,Male,1
1,Kaminda George Willems,12.1529341,-68.8739812,Female,1
1,Kaminda George Willems,12.1529341,-68.8739812,Morto,0
1,Kaminda George Willems,12.1529341,-68.8739812,No interna,2
1,Kaminda George Willems,12.1529341,-68.8739812,Zone,2
1,Kaminda George Willems,12.1529341,-68.8739812,Dagdeel,Nacht
2,"Kaya Tronchi, Grote Berg",12.1930128,-69.0030296,Male,2
2,"Kaya Tronchi, Grote Berg",12.1930128,-69.0030296,Female,0
2,"Kaya Tronchi, Grote Berg",12.1930128,-69.0030296,Morto,0
2,"Kaya Tronchi, Grote Berg",12.1930128,-69.0030296,No interna,2
2,"Kaya Tronchi, Grote Berg",12.1930128,-69.0030296,Zone,1
2,"Kaya Tronchi, Grote Berg",12.1930128,-69.0030296,Dagdeel,Avond
3,Kaminda Laurentius M. Mathilda,12.1649545,-68.9590925,Male,0
3,Kaminda Laurentius M. Mathilda,12.1649545,-68.9590925,Female,2
3,Kaminda Laurentius M. Mathilda,12.1649545,-68.9590925,Morto,1
3,Kaminda Laurentius M. Mathilda,12.1649545,-68.9590925,No interna,1
3,Kaminda Laurentius M. Mathilda,12.1649545,-68.9590925,Zone,1
3,Kaminda Laurentius M. Mathilda,12.1649545,-68.9590925,Dagdeel,Avond