I-485 Processing Time Line

Could anyone resolve this problem:

For Nebraska Service Center:
According to the US Immigration Office website, for I-485 it needs 570-600 days after the application received. But its website also says that the proccessing dates for cases is 9/30/2001, this means that it needs about 1000 days (9/30/2001 - 3/4/2004).

What is right?

Referent websites:
http://uscis.gov/graphics/index.htm

https://egov.immigration.gov/graphics/cris/jsps/index.jsp?textFlag=N#

https://egov.immigration.gov/graphics/cris/jsps/index.jsp?textFlag=N

Thanks!