The back-to-back stem-and-leaf plot below shows the ages of patients seen by two doctors in a family clinic in one day. Compare the ages of the patients of doctor 1 and doctor 2 using the mean and the median of each data set. 
Doctor 1 Doctor 2 
| 3 | 5 
9 2 0 | 2 | 0 0 2 3 6 
8 7 5 | 1 | 3 7 
9 7 3 2 1 1| 0 | 2 2 3 9 
Key: means 29 9|2|3 means 23