CREATE TABLE table_19948664_1 (countries_sampled VARCHAR2, ranking_la__2_ VARCHAR2, world_ranking__1_ VARCHAR2)

How many countries were sampled for the index in 2nd place in the LA ranking and 23rd in the world ranking?
SELECT countries_sampled FROM table_19948664_1 WHERE ranking_la__2_ = "2nd" AND world_ranking__1_ = "23rd"
SELECT "countries_sampled" FROM "table_19948664_1" WHERE "23rd" = "world_ranking__1_" AND "2nd" = "ranking_la__2_"