CREATE TABLE table_1820 ("Club" CLOB, "First season in top division" CLOB, "Number of seasons in top division" FLOAT, "First season of current spell in top division" CLOB, "Number of seasons in Liga MX" FLOAT, "Top division titles" FLOAT)

How many 'number of seasons in top division' were played if the 'first season in top division' games is in 1990-91?
SELECT MAX("Number of seasons in top division") FROM table_1820 WHERE "First season in top division" = '1990-91'
SELECT MAX("Number of seasons in top division") FROM "table_1820" WHERE "First season in top division" = '1990-91'