CREATE TABLE table_28868 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" TEXT, "Result" TEXT, "Candidates" TEXT)

How many people were first elected when john roane was the incumbent?
SELECT COUNT("First elected") FROM table_28868 WHERE "Incumbent" = 'John Roane'
SELECT COUNT("First elected") FROM "table_28868" WHERE "Incumbent" = 'John Roane'