No one knows for sure but you can kind of guesstimate using the college. The College’s acceptance rate is always, nearly exactly the same as the overall school acceptance rate because it makes up the largest contingent of the undergraduate student body and thus has a disproportionately larger affect on the weighted overall admit rate. for example, in the article below from the DP in 2003, the College’s admit rate was 19.4%, Wharton’s was 15.5%, SEAS was 28.1%, Nursing’s was 42.6% and yet the overall admit rate was 20.5%. If the schools were all averaged together equally, the overall admit rate would have been higher. Alternatively, if the overall admit rate was just the average of the ED and RD admit rate, then the RD admit rate back in 2003 would have had to be about 8% (which it wasn’t), in order for the overall rate to be 20.5 But because each school’s admit rate is weighted, the rate most closely mirrors that of the College. So you can assume that the College’s admit rate is about 9-10%, Wharton and engineering are a bit lower (probably 8-9%), and Nursing is usually higher (probably 15-16%). As you can see in both the 2003 article and this article from 2010 showing the nursing admit rate to be about 20% while the overall admit rate was 14.2%, penn nursing tends to be about 5-6% points higher than the overall.
http://www.thedp.com/index.php/article/2003/04/admission_rates_drop_at_penn_ivies
http://www.thedp.com/article/2010/02/decisions_sent_to_nursing_hopefuls
http://www.huffingtonpost.com/2010/03/31/penn-acceptance-rate-fall_n_519942.html