 Pari gbolohun yii: Jansen gba akọkọ ninu awọn akọle orilẹ-ede Dutch mẹta ti o tẹle ni akoko 1977  78. O kopa ninu idije ISU marun-un, o pari ni ipo 17th ni 1978 Europeans ni Strasbourg, France; 18th ni : 1978 Worlds ni Ottawa, Ontario, Canada; 20th ni 1979 Europeans ni Zagreb, Yugoslavia; 23rd ni 1979 Worlds ni Vienna, Austria; ati 18th ni 1980 Europeans ni Gothenburg, Sweden. 