So, first off, that number is not the average, it's the median. Quoting from Table2 "Data are presented as median (25th percentile–75th percentile]." The paper isn't on nonfree testosterone in general, but in the opening statement the implication is the tail is rather long
"Among the 1332 female observations,
44 showed an fT concentration >29.4pmol/L.17 Twenty-four
female athletes showed a T concentration >3.08nmol/L which
has been calculated to represent the 99th percentile in a previous
normative study in elite female athletes."
The performance advantages they measured, in the events inwhich there were any, are explicitly linked to fT not non free testosterone and even then aren't being presented as causative.
"Our study design cannot provide evidence for causality
between androgen levels and athletic performance, but can indicate associations between androgen concentrations and athletic
performance. Thus, we deliberately decided not to exclude
performances achieved by females with biological hyperandrogenism and males with biological hypoandrogenism whatever
the cause of their condition (oral contraceptives, polycystic
ovaries syndrome, disorder of sex development, doping, overtraining). As a consequence, the calculated mean fT value in
the present study is higher than the 8.06pmol/L median value
previously reported in a similar female population."
They certainly don't appear to be arguing that hyperandrogenism in women should be a disqualifying condition. Especially in running events like the ones Semenya competed in since the performance gains appear most significantly in the throwing events.
"Our hypothesis is that ...androgens exert their
ergogenic effects on some sportswomen through better visuospatial neural activation."