Depends on what your perspective of "normal" is.
"Normal families" are a lie made by families who see themselves as dysfunctional to set a standard to achieve to "better" their family
functionality is a continuum. All families are functional to degrees and also dysfunctional to degrees. I suppose there is a tipping point at which normal levels of dysfunctionality is considered serious enough to entirely define the family as dysfunctional but it is a constructed rather than real categorisation. So yes more families are normal than dysfunctional but only because that is how normal families want it to be. Dysfunction is inevitable and even healthy as life is dysfunctional and we need to be exposed to problems in childhood in order to learn how to survive.
There is no such thing as a functional family.