Write a Python function `graphSnowfall(t)` which retrives data in a text file _t_ and displays that information in a bar chart. The file will have a single number on each line representing the amount of snowfall accumulation for a given day. Aggregate these values so that each one contributes to a particular 10 cm range.

For example, a file containing 10 15 45 5 20 25 would have * 2 between 0-10cms * 2 between 11-20cms * 1 between 21-30cms * 0 between 31-40cms * 1 between 41-50cms