CREATE TABLE table_name_15 (_number_of_cosponsors VARCHAR, date_introduced VARCHAR)

How many cosponsors have a Date introduced of may 22, 2008?
SELECT COUNT(_number_of_cosponsors) FROM table_name_15 WHERE date_introduced = "may 22, 2008"
SELECT COUNT("_number_of_cosponsors") FROM "table_name_15" WHERE "date_introduced" = "may 22, 2008"