Bash Shell Script Array Length Off By One

The length of an array in my bash shell script appears to be off by one. I have 11 elements in a text file that I am reading in to an array, but my array length seems to be 12.

(( count = 0 ))
while read students[$count] ; do
    (( count++ ))
done < students.dat

echo $count

ArrayLength=$((${#students[@]}))

echo $ArrayLength

This code outputs:

11
12

The 11 makes sense since the count increment occurs after the read occurs and starts with 0--indicating 11 elements read in.

But the 12 is mysterious.

Here is the data file:

Ann
Bob
Cindy
Dean
Emily
Frank
Ginger
Hal
Ivy
Justin
Karen

(names appear on their own lines, but I couldn't format it that way in this post)

I've double checked with multiple utilities and there is NOT a blank line at the end of the file, or any trailing spaces on any line.