it's been several years since stats class, but i think that's enough information to let you estimate the mean and standard deviation, which will let you estimate the top 10% and top 15% numbers.

i'm using the z-score chart here:

http://zenhome.home.att.net/stattables.pdfit shows that the z-score corresponding to to 25% is 0.67, and for top 5% is 1.64. figuring that z = (X - m)/s, where X is the data point, m is the mean, and s is the standard deviation, i calculate a mean of 3.39 and a standard deviation of 0.309. going back to the chart, top 15% would be a 1.04 standard deviations above the mean, or 0.32 points above the mean, or 3.71. top 10% would be 1.29 standard deviations above the mean, or 0.37 points above the mean, or 3.76.