  SU UMa stars are characterized by "superoutbursts" which are brighter at
maximum light and which last much longer than the more frequent "ordinary"
outbursts of these dwarf novae. Although there are now more than 1180 SU UMa
type dwarf novae catalogued, our knowledge on their superoutburst cycle length
Cso was hitherto limited to about 6$\%$ of the entire sample of known SU UMa
stars. Using public data bases we have determined new Cso values for a total of
206 additional SU UMa stars in the range 17 d $<$ Cso $<$ 4590 d (including
some ER UMa and WZ Sge type representants) within total time intervals between
2 and 57 years, and with an estimated uncertainty of $\pm$11$\%$. This way, we
are increasing our present knowledge of Cso values by a factor $\sim$3.8. Its
distribution is characterized by a broad maximum around Cso $\approx$ 270 days,
and slowly decreasing numbers till Cso $\approx$ 800 d. The domain Cso $>$ 450
d was unexplored until now; we add here 106 cases ($\sim$51$\%$ of our total
sample) in this range of long cycles, implying a better statistical basis for
future studies of their distribution. Our sample contains 16 known WZ Sge
stars, and we propose WZ Sge membership for 5 others hitherto classified as
ordinary SU UMa stars. Individual superoutburst timings deviate in average
about $\pm$7$\%$ of the cycle length from their overall linear ephemeris,
conrming a pronounced quasi-periodic repeatability of superoutbursts. All
relevant parameters are listed with their errors, and a table with individual
superoutburst epochs of our targets is given, enabling future researchers to
combine our results with other (past or future) observations.
