I didn't find any online studies about high school grade levels.
In my opinion, it doesn't make much difference what you call the school that houses any grade. There is no natural difference between 8th and 9th grades or 9th and 10th grades. Divisions between schools usually depend on the rooms available, especially in small districts.
I assume that you are a 9th grader in a middle school with 7th and 8th graders and believe you should be in high school. If appropriate 9th grade classes are available to you, then enjoy being the kings/queens/leaders of your middle school, rather than being lowly freshmen in high school.
No, I'm a 10th grader in High School now, but after leaving a 7-8th grade Middle school to go to a 7-9th grade middle school, the differences became painfully clear.
Anyhoot, thanks for your attempt!
No matter whether the 9th grade is in a middle school or a high school, the transition to high school (10-12) is often difficult for students. The good news is that most colleges and universities look at the grades in 10-12.
Try researching about the emotional levels of teens that age, also the maturity level, intrests, what they are going through. Think of reasons why they shouldn't be in the high school system yet and google those. (2 years of newspaper paid off!)