See here Measuring Shielded Adoption for stats until end of April (I’ll update May in a few days). Currently fully shielded tx account for 6% (which is at an all-time high), I think the figure you reference includes all shielded components i.e. shielding/deshielding.
Generation time is a little nuanced as it depends on the transaction type and the number of inputs/outputs but of the order of a few seconds for a fully shielded tx.