Not spliting by months

Dear friends,

I’m using this plugin (it’s the best!) but I have a little problem… the sitemap files is not splitted in months. You can see at:
https://www.esportesite.com.br/sitemap-posttype-post.20136.xml

I thought the sitemap file “20136” should contain only the posts of the month 06 of 2013, but no, all posts are coming from the year 2013 in the same file.

This happens for the previous years as well.

It is possible that only the posts of that month to appear in the sitemap files?

https://www.ads-software.com/extend/plugins/bwp-google-xml-sitemaps/