A bakery times how long each customer spends in the queue. The 30 recorded queue times, in minutes, are summarised in this frequency table:
| Queue time (min) | Frequency |
|---|---|
| 2 | 5 |
| 4 | 10 |
| 6 | 6 |
| 9 | 5 |
| 16 | 2 |
| 50 | 2 |
By how much does the mean queue time exceed the median queue time?
Answer in minutes, rounded to 2 decimal places.