Top margin of Ai image in content box varies

Hi All,

When I place an Illustrator file into a text frame in Indesign, the space at the top of the content box varies from one illustration to the next. In the attached example, you can see that the image I-26 has no space between the art and the top of the bounding box. In I-27 there's a little space, and in I-28, there's a little bit more. What do I need to adjust in order to get this spacing to be consistent?

Also, you can see that the art is flush left within the bounding box. The art needs to be centered, but it always comes in with space on the right. To center it, I'm having to adjust the bounding box for each individual piece of art. Is there away to set this as a style? I've tried object styles, but didn't find anything that did the trick.

If it helps to answer questions—

Art is always placed 100% and then I use the Fit Frame to Content button.

I use Paragraph Styles to style the space that I place the art into (in the text frame).

As far as I know, there are no invisible objects left on the page in illustrator that would add the extra space to the right. This does happen occasionally, but it's always obvious when it does. The vast majority of the art comes in as pictured.

Can anyone shed some light on why this is happening and how to fix it?

Thank you,

Kathy K