Centaurus
I have frequently seen student log books where after first solo, the next 5-8 hours are dual followed by another short solo and so the ratio of dual to solo steadily seems to increase in favour of dual. Often this is due to some instructors "milking" the hapless student to pick up more money and/or to fill his own log book.
This has been the subject of other threads, but if I may I would offer a possible alternative explanation:
The overall aptitude of pilot trainees seems to be diminishing with very few people being hands-on "how does this work?" types. The instructors are often under pressure (internal or student-applied or employer-applied) to send a stude solo so the student can "make progress" ...despite their lack of progress.
That box ticked, the stude then needs a fill of more dual because they have passed the bar, and slacked off.
Alternately they go solo (however deservingly) and then don't fly for weeks.
I can't say I know of many CFIs who are so venal as to milk students, but then I only get to speak to other small-school CFIs.