CREATE TABLE table_70378 ("Year" FLOAT, "Division" TEXT, "League" TEXT, "Regular Season" TEXT, "Playoffs" TEXT, "U.S. Open Cup" TEXT, "Avg. Attendance" TEXT)

What year did the team make conference semifinals?
SELECT COUNT("Year") FROM table_70378 WHERE "Playoffs" = 'conference semifinals'
SELECT COUNT("Year") FROM "table_70378" WHERE "Playoffs" = 'conference semifinals'