As already mentioned, ADSL2/2+ will vary depending upon your distance from the exchange.

But keep in mind with any ADSL, ADSL2/2+ general guides or rules are only that. There are many other variables to consider with regards to connection/performance speeds.

Some of the variables include;
-Quality of the physical phone line between you and the exchange.
-Environmental conditions on the exchange equipment, the phone line, and your own equipment.
-Quality of the phone line throughout your house.
-Having your house physically right next door to the exchange is no guarantee your phone line is right next door to the exchange, nor is it going to guarantee the best performance.
-ADSL line filters are often the cause of most ADSL related problems/speed issues etc, LSE filters (try OzTechnologies.com, or me if you live close) I have found to be without exception the best filters to use.
-The ADSL modem/router supplied by your ISP generally is used because they have a good purchasing agreement with the supplier and is not a given it's the most ideal device for any given situation.
-Other equipment (phones etc) including between your phone outlet and the ADSL device, such as surge protection equipment.
-Your ISP and their equipment.

Best regards
DarrenR