Some of my photos i developed were not visible, just grey, what happened?

I'm using a nikon f100 with fujifilm film and only 11 exposures were visible, the rest were just grey. Most pictures i took were from outside in california weather. I know my shutter speed, aperture, and iso were fine and exposed properly. (i looked at the meter). Please help me i don't know what to do or how to fix this.

My guesses would be:

1. Your shutter is sticking or broken, or,

2. If your camera has an electric eye, it's not working.

First let's rule out film processing. Film is pre-exposed, at the factory with frame numbers, emulsion number, and other markings which may be symbols. Edge printing is exposed using a printer that prints with light. This labeling can be a great help to diagnose film processing errors. Carefully examine this edge printing. The density (blackness) of the letters, number and symbols should be bold and uniform in density end-to-end. Look at the labeling on blank and gray frames as well as well exposed and well developed frames. Is the edge printing uniform? If the answer is yes, the blame falls on the camera. If not uniform, look to improper fluid volumes or agitation. A common problem is insufficient fixing. If true you can re-fix and re-wash to remedy.

It sounds like they were over exposed. The reasons could be many.