How many 'number of season in Liga MX' were played if the 'first season of current spell in top division' is in 1962-63?
create table table_18143210_2 (number_of_seasons_in_liga_mx varchar, first_season_of_current_spell_in_top_division varchar, PRIMARY KEY (number_of_seasons_in_liga_mx))
select number_of_seasons_in_liga_mx from table_18143210_2 where first_season_of_current_spell_in_top_division = "1962-63"