incomplete POST sitemap

Hi everyone…
I’m using wp 3.8 & the latest version of wordpress seo.

yesterday i found that may site map : http://www.i98.ir/post-sitemap.xml
is incomplete & showing just 2 of my posts !!!
i have 173 post exactly 😀

Can anyone help me to fix this problem ?!

http://wordpress.org/plugins/wordpress-seo/