CREATE TABLE table_19191 ("Year" FLOAT, "League" TEXT, "Reg. Season" TEXT, "Playoffs" TEXT, "US Open Cup" TEXT, "Avg. Attendance" FLOAT)

What was the regular season standings for the year when the playoffs reached the conference semifinals and the team did not qualify for the US Open Cup?
SELECT "Reg. Season" FROM table_19191 WHERE "Playoffs" = 'Conference Semifinals' AND "US Open Cup" = 'Did not qualify'
SELECT "Reg. Season" FROM "table_19191" WHERE "Playoffs" = 'Conference Semifinals' AND "US Open Cup" = 'Did not qualify'