Thank you on your reply, but I have already tried self.year_drop_down.selected_value
I wrote it in answer:
With self.year_drop_down.selected_value I get value 1 or 2 depending on the selected year.
What I want is to get 2002 or 2003 from the items, that is price_per_years.
price_per_years = [
("2002", 1),
("2003", 2)
]
self.year_drop_down.items = price_per_years