Table:
text: List of Formula One World Drivers' Championship runners-up
By season
By season
Season Driver Team Engine Poles Wins Podiums Points Margin_of_defeat
1969 Jacky Ickx Brabham Ford 2 2 5 37 26
1970 Jacky Ickx Ferrari Ferrari 4 3 5 40 5
1971 Ronnie Peterson March Ford 0 0 5 33 29
1972 Jackie Stewart Tyrrell Ford 2 4 5 45 16
1973 Emerson Fittipaldi Lotus Ford 1 3 8 55 16
1974 Clay Regazzoni Ferrari Ferrari 1 1 7 52 3
1975 Emerson Fittipaldi McLaren Ford 0 2 6 45 19.5
1976 Niki Lauda Ferrari Ferrari 3 5 9 68 1
1977 Jody Scheckter Wolf Ford 1 3 9 55 17
1978 Ronnie Peterson † Lotus Ford 3 2 7 51 14

Question: How many seasons was Clay Regazzoni the driver among the runners-up in the Formula 1 World Drivers' Championship?