Hi Jenny,
The sugar is lactose. That's not fructose, so it's ok to have. The nutrition information label doesn't list the types of sugar that go into the amount. With milk, about that much is lactose, and if they add sugar, then the sugar amount is part of the total.
I'd just check the ingredients on yogurt- if sugar is listed, don't eat it. I buy the plain yogurt and add a tsp of glucose to cut the tartness. With a piece of fruit, it's yum.
Dennise