Additionally, if someone is taking an intro class in the Spring, that's probably because they already failed it in the previous semester. While that doesn't guarantee that they'll fail again, it does make it more likely.
Separately, there's a clear downward trend in the number of grades being awarded in the fall semester. Perhaps students have the option to take the course pass/fail?
That doesn't mean there isn't a problem worth investigating. If I was a dean I'd certainly have some questions if I found out that 35% of students failed a class. But without knowing the specifics it's irresponsible to draw any conclusions about these 34 students with the limited data we have available.
That's why I raised the low N.