CREATE TABLE table_204_28 (id DECIMAL, "election" TEXT, "name of the party/alliance" TEXT, "number of votes" DECIMAL, "percentage" TEXT, "seats in the parliament" DECIMAL)

how long from the first election date did the elections go on ?
SELECT MAX("election") - MIN("election") FROM table_204_28
SELECT MAX("election") - MIN("election") FROM "table_204_28"