Thanks for sharing your list Jim!
Don't know if anyone cares but in the hopes of others sharing here are my top Bio's
BMRN (curr holdings ~9 years but sold some bought 15 years ago)
FGEN (held avg ~2.5 years)
GLPG (held avg ~3 years)
CLVLY/F (held avg ~2.5 years)
ABEO (held avg ~11 months, Was small orig position grew faster than exp.)
CTMX, NKTR, SRPT (shares + options) are also significant holdings