That is normal. Sex hormone binding globulin binds about 98-99% of total circulating sex hormone in the blood. Only the unbound fraction is biologically active. The total serum level is indicative of how much is being produced by the gonads.
If you want an in-depth explanation, you should PM KayXo (once you have 15 posts). She is really on top of that stuff.
With kindness,
Terri