The phrase "insufficient data" means that there is not enough information or evidence to come to a clear conclusion or make a certain decision. Full definition
There was also insufficient data for the task force to determine whether or not healthy younger women and men of any age should take the supplements. (scientificamerican.com)
In the outside world, decisions often must be made with insufficient data because of time constraints. (sciencemag.org)
We have insufficient data due to lack of dealers in your area. (truecar.com)