finger print & 485

File I-140 and I-485 at the same time on 2004. Don't remember the exactly date.

Take 1st finger print on 1/18/2005. Take the finger prints for all 10 fingers.

Take 2nd finger print on 7/14/2005. This time only take the finger print for right index finger. Don't know why it's different with the 1st time?

How many finger prints I need to take before the I-485 approval? How long can I get the 485 approval after take the last finger print?

Thanks