SELECT MAX(number_of_seasons_in_top_division) FROM table_18143210_2 WHERE first_season_in_top_division = "1990-91"
Berapa banyak 'jumlah musim di divisi teratas' yang dimainkan jika pertandingan 'musim pertama di divisi teratas' pada tahun 1990-91?
CREATE TABLE table_18143210_2 (number_of_seasons_in_top_division INTEGER, first_season_in_top_division VARCHAR)