Complex sentence: This started a yo-yo era that led the club to be known as the "elevator team"--promotions were achieved in 1962,1964,1966,1968 and 1971, yet subsequent relegations occurred during 1963,1965,1967,1970 and 1973.
Split into simpler sentences: This started a yo-yo era that led the club to be known as the "elevator team". Subsequent relegations occurred during 1963,1965,1967,1970 and 1973.