Table:
text: Johnny Walker (actor)
Filmography
1970-1979
Song Singer Co_Singers Music_Director Lyricist Co_Stars Movie_Album Year_ Additional_Info
Pyar Karnewale Pyar Karte Hai Shaan Se Asha Bhosle N/A Rahul Dev Burman Anand Bakshi Parveen Babi Shaan 1983 Club Attendee and Dancer
Mere Jawani Ter Deewani Asha Bhosle N/A Rahul Dev Burman Anjaan Helen Hungama 1971 Nautanki Dance Attendee

Question: How many co-singers were there when Parveen Babi starred in Johnny Walker's (actor) filmography from 1970-1979?