Second half of the nineties.
There had been also some kind of riser bars already for mid 80ties ATBs.
Then a few years of flat bars only for MTBs.
Riser got just popular again with the raise of DH bikes, roughly 94/95.
Also known brands like Answer, Syncros, Club Roost or Azonic started to offer DH bars with high rise.
The extra brace is a typical sign for a downhill bar of that time.
From around 2000 onwards most regular bikes came then by default with low riser bars.
Uno Kalloy is a Taiwanese brand, qualtity-wise fine, but rather no hot shit.