This is a measurement that can be useful in racquet selection, as both the weight, and balance is taken into consideration. The values are available from some companies and not others. It is not a value that can easily be measured.
There are some places where you can find the information. One of these is the Tennis Warehouse website, which lists most current models. Another source is available from the Tennis website, where there is a racquet Selector. This lists most models and shows several other measurements which you could find useful.