A request for differential data relative to a first data element within a group of data elements is received via a user input device. A first differential data value for each of the group of data elements relative to the first data element is calculated. The first differential data value for each of the group of data elements relative to the first data element are displayed on a display in response to the received request. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.