Help! Three years pre vs three years post

I"m doing an educational study in which I am analyzing the effectiveness of a particular academic program. I am looking at student scores for three consecutive years prior to the implementation and comparing them to three consecutive years prior to see if the program has any measurable effect. I would typically go with a t-test if it was a single year compared to a single year, but how would I do it differently with three years vs three years?


Not a robit
Please provide more information, such are does each student has 6 observation or not. Also, what is the sample size and distribution of scores? Did people get 100% on the exam?
Let's say I teach a math course with 30 students enrolled. I teach this course for three years, with different students each year. In between years three and four I implement a new academic program. I keep this program for years four, five, and six. At the end of each year, the students take a standardized assessment. I want to compare the collective scores from years 1-3 to the scores from years 4-6 to measure the program's effect, if any.