I got the same numbers - here is the data in case anyone is interested.

Looking at one prep going into the Derby did not yield anything too interesting as far as I was concerned. Since the archives go back to 1997, I used that as a starting date and looked through to find any starters with one prep. There were only seven horses that had one prep. Two were from Saeed bin Suroor, four were from Aidan O’Brien and one was from William Currin. Currrin trained Outta Here who is the only US horse (So Cal) but he did compete in the UAE Derby. The rest were foreign horses and a couple had won or participated in the UAE Derby. Analysis was difficult as there a couple of horses that had no 2YO foreign figures. I have summarized their performances below. The data points are few in nearly 25 years and they were a mixed bag. A new top, a couple of paired tops, and couple of X’s including one being eased and couple where there were not any 3YO figure to make an assessment. I also added the only entrant in that time span without a prep.

0 Prep Race
1999 Worldly Manner - 9/9 8.5 (paired top); 5/1 6.25 (new top) bin Suroor, Saeed

1 Prep Race Since 1997
2000 China Vista - 3/25 8.00 (top – only figure); 5/6 5.50 (new top) bin Suroor, Saeed
2001 Express Tour – 3/24 2.00 (top – 2YO top 5.00); 5/5 7.25 (X) bin Suroor, Saeed
2002 Johannesburg – 4/7 ?.?? (no figure – 2YO Top 6.25); 5/4 6.25 (paired 2YO top ) O'Brien, Aidan P.
2002 Castle Gandolfo – 4/6 ?.?? (no figure – no 2YO figures); 5/4 7.00 (???) O'Brien, Aidan P.
2003 Outta Here – 3/29 8.25 (2YO top 2.75); 5/3 3.25 (paired 2YO top) Currin, William L.
2012 Daddy long Legs – 3/31 5.00 (2YO top 7.75); 5/5 XX (eased – no figure) O’Brien, Aidan P.
2013 Lines of Battle – 3/30 4.25 (2YO top 9.00); 5/4 5.00 (paired 3YO top) O’Brien, Aidan P.