First, get a view of the distribution of data by sorting it, then creating a frequency distribution.
Now, determine the Quartiles:
The first quartile, denoted Q1, is the value in the data set that holds 25% of the values below it.
Q1 = 109
The third quartile, denoted Q3, is the value of he data set that holds 25% of the values above it.
Q3 = 119
Q2 = 115 [mean]
Interquartile Range (IQR) = Q3-Q1 = 119 - 109 = 10
Outliers: 129, 135 (see frequency chart)