Hmm that site concerns me a bit... I looked at some of the past missions and it makes no mention of one US troop ever serving in Rwanda, I find that interesting and I am sure the 160th nightstalkers and a few other units would as well...
It's because the 160th nightstalkers didn't go to Rwanda, they went to Somalia.
If you check the UN Peacekeeping website for the past missions in Somalia, you'll find a mention of the US among the "Contributors of Military and Civilian Police Personnel" for UNOSOM II.
I don't know how many Americans of the 160th there were in Somalia in total, but the data given for UNOSOM II mentions a full total of some 15,000 UN peacekeepers, plus international staff. So if you know how many Americans of the 160th there were, you can roughly calculate the proportion they constituted of the total.
I also don't know how many Americans died in Somalia, but in total the UN peacekeepers apparently suffered 151 fatalities there. Again, if you know the American number you can calculate how big a share of the suffering the US took.
And no US troops in Rwanda then, that would be right.
(One can generally trust a site like the UN's to give the right credits - they would never get away with giving the wrong numbers, too many Member States checking what they put up. ;-))