Recent observations led me to think Philips 07XXX series (for jazz, big band and other more popular genres) were released according to the following scheme:
070XX Most releases before 10/1956
071XX Released from 1956 onwards
072XX Released later than 9/1956
073XX Released later than 9/1956
074XX Non-existent
075XX Released later than 9/1956
076XX Most releases before 10/1956
077XX Most releases before 10/1956
078XX Non-existent
079XX Non-existent
This means that the 070XX, 076XX and 077XX ranges were released first, than came 071XX, to be followed by 072XX, 073XX, 075XX.
Sources: My own collection, Discogs and especially the Philips catalog “Amerikanische Serie, Hauptcatalog 1956/57”, which lists releases published before Sept. 30, 1956. When going through the pages all I can find are issues from the 070XX, 076XX and 077XX ranges and a few from the 071XX range.
More research is needed though.