ten year L visa eligibility

Hello

I am a Canadian citizen. For the past ten years i have traveled extensively to and from China. Originally i traveled for business purposes. Now I am retired. However i have many friends and acquaintances in PRC and since my retirement have spent a great deal of time there. I maintain an apartment in Beijing where i stay when I am in PRC.

Currently I have a twelve month multi entrance L type with ninety day stays.

First, am I eligible to obtain an extended entry permit up to ten years with six month stays>?

Second, what documentation is required?