AFI Top 25 Film Scores

Decided by a jury of 500-ish musicians and whatnot, via the American Film Institute.

1. Star Wars – 1977 – John Williams
2. Gone With The Wind – 1939 – Max Steiner
3. Lawrence of Arabia – 1962 – Maurice Jarre
4. Psycho – 1960 – Bernard Herrmann
5. The Godfather – 1962 – Nino Rota
6. Jaws – 1975 – John Williams
7. Laura – 1944 – David Raskin
8. The Magnificent Seven – 1960 – Elmer Bernstein
9. Chinatown – 1974 – Jerry Goldsmith
10. High Noon – 1952 – Dimitri Tiomkin
11. The Adventures of Robin Hood – 1938 – Erich Wolfgang Korngold
12. Vertigo – 1958 – Bernard Herrmann
13. King Kong – 1933 – Max Steiner
14. E.T. – 1982 – John Williams
15. Out of Africa – 1985 – John Barry
16. Sunset Boulevard – 1950 – Franz Waxman
17. To Kill a Mockingbird – 1962 – Elmer Bernstein
18. Planet of the Apes – 1968 – Jerry Goldsmith
19. A Streetcar Named Desire – 1951 – Alex North
20. The Pink Panther – 1964 – Henry Mancini
21. Ben-Hur – 1959 – Miklos Rozsa
22. On the Waterfront – 1954 – Leonard Bernstein
23. The Mission – 1986 – Ennio Morricone
24. On Golden Pond – 1981 – David Grusin
25. How the West Was Won – 1962 – Alfred Newman

My question is: are there so few recent scores on this list due to a mathematical reason (more movies produced prior to 1980 than after), a quality reason (older scores simply better, on the whole), or an aging reason (a score needs to “age” before its impact can be accurately judged).  No answers here.