Given this paragraph about the Republic of Finland becoming a member of the North Atlantic Treaty Organisation (NATO) what year did it start a formal relations with NATO?

Finland has had formal relations with NATO since 1994, when it joined the Partnership for Peace program, and has been a member of the European Union (EU), which largely overlaps with NATO in membership,[clarify] since 1995.

Finland has started the formal relationship with NATO in 1994 when it joined the Partnership for Peace program. However it wasn't a NATO member up until April 4 2023 when it became an official member of NATO.