Table:
text: Maxie Parks
Best performances
400 meters
Year_ Result_ World_Rank Location_ Date_
1973 45.5 9th Bakersfield Jun 16
1974 45.76 11th Austin Aug 24
1975 45.9 30th Bakersfield May 17
1976 44.82 4th Westwood Jun 12
1977 45.45 7th Zurich Aug 24
1978 45.15 6th Westwood Jun 10

Question: What world ranking happened for Maxie Parks in 1977?