Reducing size of graph title while using by option in histogram

[Aleesha Mary Joseph]

I generated this graph using the following code:

local k=0
ds vpast*
foreach i of varlist `r(varlist)'{
local k = `k'+1
hist p170, percent by(`i',note("") compact) name(hist`k') xtitle("")
graph save hist`k' "$gwave1\past_violence\hist_belief_verbabuse_`i'.g ph" , replace
}

graph combine hist1 hist2 hist3 hist4, name( verbabuse_vpast) title("Belief about patner being verbally abusive to you in the next 12 month")
graph export "$gwave1\past_violence\hist_combined_belief_verbab use_vpast.png", replace

I want to reduce the size of the title of each subgraph in this figure to avoid the cluttering of titles that can be seen in the first panel of the figure. I tried changing the by option in the following way: by(`i',note("") compact title(,size(small))) . However, this didn't work. I have tried similar variations like subtitle and caption also. None of this worked. How can I solve this issue? Thanks in advance.

[George Ford]

you'd think , subtitle(, size(tiny)) would work but it doesn't.

you can change it in the data editor, save it, then re-run it when needed.

but I suspect there's a direct trick, but can't figure it out.

[Andrew Musau]

you'd think , subtitle(, size(tiny)) would work but it doesn't.

This works for me. The option should be placed outside -by()-.

webuse census, clear
hist pop, by(region) subtitle(, size(tiny))

[George Ford]

Doh! Thanks Andrew.

[Nick Cox]

You could shorten it too.

[Aleesha Mary Joseph]

Thank you so much everyone! Andrew's solution worked smoothly

[Nick Cox]

In your best interests I suggest fixing the typos

Belief about patner being verbally abusive to you in the next 12 month

and shortening to say

Will partner be verbally abusive in next year?

It would be good practice no doubt to give the exact wording somewhere, but once you do that no-one should mind concise equivalents in graph titles.