You can refer to your statistics from My websites then Statistics. A drop-down menu on the top left will enable you to choose a customized period (for instance, from the date of creation of the website).
You will find more detailed information in the guide on Traffic analysis for your website.
If the period you wish to refer to is large, the loading time will be relatively long (the results come from Google Analytics and this waiting time is beyond our control). In order to get more statistics, and, for quicker searches, we advise you to create your own Analytics account and to configure your website so that all visits are registered over there. You will find more detailed information in the Install Google Analytics on your website guide.