I have a *sitemap.xml* index fine with 3 XML files in it with around 120 pages for indexing.
A year passed and I still have 1/3 of it indexed. All the most important pages for indexing are in 1st sitemap file, however Google takes a similar amount from each of the sitemap files instead...

How to make Google index all *sitemap.xml* records?

I have crawl rate set to MAX in GWT.