It not a matter of performance appraisals for teachers who are performing. In such a case as you have shown in your post, it would have to be a rolling value based on three years worth of data to normalize the variations from year to year.
The key is not to grant tenure at all, or but make such a grant be after 10 years of performance as opposed to three.
Even rolling values can be quite skewed. One extremely disruptive student in a class two years in a row will destroy test grades.
IMHO, the main problem with most public schools is not the inability to get rid of bad teachers (although they certainly do exist).
It’s the inability to get rid of chronically disruptive students.
By the way, you can substitute “lack of will” for “inability” in my post. Same thing.