They only count kickoffs that are actually returned. We kicked the ball off ~70 times this season. We had 26 kicks returned for 609 total yards. That's a pretty effective kickoff unit in comparison to others. On a 'total yards' basis, we're 27th in the country. That's after Fournette's return. We'd be in the top 10 without it.
I think average starting field position would be a much more effective measure of kickoff effectiveness. But I don't think the data is available to calculate it.
Besides Fournette's kick return in the Music City Bowl, did we have any returns of significance?