Does this mean my i-485 was approved? Urgent

I found that my application for I-485 has this:

Application Type: I485, Application to Register Permanent Residence or to Adjust Status

Current Status:

On October 20, 2005, the document we made based on the approval or registration of this case was mailed directly to the person to whom issued.

Does this mean my i-485 was approved long time ago? but I had never received this document. I am confused.