Annotations character bounding boxes size 3 times higher than expected

After text extraction the character bounding boxes 3 times higher than expected. For example, see the first few character bounding boxes below:
[90.1,46,6.64,40.06],[96.7,46,5.09,40.06],[101.79,46,5.8,40.06].
The values are x, y, width, height. The width of the characters are between 5 and 7 pixels, but the height of the characters are 40.6 pixels. The actual height of each line of text appears to be about 12 pixels. The example pdf document attached.