Since you were comparing the oldest age group to a JR age group, you will find in pretty much every region that the oldest age groups at L9 (Sr 6- 8) are going to be overall lower qualifying scores compared to the other age groups as for the most part, the most talented kids are doing L10 at this age. If you look at individual regions, you will often see 34's in the higher sr groups going and 37s in the JRs not making it.
And, there is a lot of variation in sizes of regions and sizes of age groups. My dd just competed in a L10 age group of 30. The age groups for different ages and different regions varied from 3 (yes only 3!) to 35+ for L10. Before they added the 4 age groups for this year, there were age groups with 45. Even at L10 in our region the qualifying score (7th place) varied from a 37.4 to a low of a high 35.