Hi,
The index table is generated by default with 25 items per iteration to save server performance and load, in your case that was a low number, since your server performance is very high.
I have logged in to check the configuration, and removed the “attachments” custom post type from indexing, as it’s not used in the results. I also increased the “Post Limit per Iteration” option to 200, so bigger sample sizes were used. This time the indexing was successful: http://i.imgur.com/x1JLGcy.png
The items not indexed indicator might display incorrect numbers, as it includes ignored items, or items without anything to index. Your index should be fully built and working now.