And 10 years is not a "short period of time" to you?
No, 10 years isn't sufficient to say very much. I'll give you some more maths, since you love it so much

and I'm some kind of masochist who enjoys trying to educate someone who is basically putting their hands over their ears and saying "la la la I can't hear you".
The variance of SR estimates can be shown to be (1+ 0.5SR^2)/T*. Assume the SR estimate is 0.28** (by the way the data shown finishes about a year ago but let's use that number) with 10 years of returns. The variance is 0.104. The standard deviation is the square root of that is 0.322.
So we can be 95% confident that the true historical SR was in the range 0.28 - (0.322*2) to 0.28 + (0.322*2) i.e.
in the range -0.36 to 0.92. If we take Winton for example with roughly 20 years of data and a SR of about 0.6
the range is 0.11 to 1.09.
Twenty years of data is
barely enough to show that there is statistical evidence that Wintons returns are positive. However they could plausibly be just above zero or over one.
Ten years of data tells us basically nothing. So actually it's a moot point whether the estimated SR of Cantab was 0.28, 0.5 (in which case the range would be -0.17 to 1.17) or something else.
Seriously having a better intuitive understanding of statistics will make you a much better trader, even if you don't want to start wearing glasses, developing poor hygiene and calling yourself a "data scientist" or "machine learning guru".
GAT
* this relies on certain assumptions but for CTA type strategies*** with typically negative return autocorrelation this probably overstates the variance, i.e. we are being conservative. See Lo, 2002
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.460.3450&rep=rep1&type=pdf
** Not that it matters but I hand calculated the SR for Cantab in my head and obviously got it wrong, for the time period shown it is 0.28. However there is about a year of missing data so I don't actually know what the latest estimate for Cantabs SR is.
*** Lo doesn't consider the effect of skew and I need to do the maths on this myself since I can't find anyone else who has looked at it, but my intuition is that large positive or negative skew makes the variance of the SR wider.
EDIT: I've just found this paper
https://cran.r-project.org/web/packages/SharpeR/vignettes/SharpeRatio.pdf and page 13 is relevant