Try this for creating a calculated column called Occurrences:
Occurrences =
CALCULATE (
COUNT ( [Pais] ),
FILTER (
'Table',
[Index] <= EARLIER ( 'Table'[Index] )
&& [Pais] = EARLIER ( 'Table'[Pais] )
)
)
Index must be an incremental key in each row.
Let me know if this helps.