Outliers are those values in the data set that are beyond 1.5 times the IQR past the end of the "box" in the "box-and-whisker" plot.
The IQR is 187-139 = 48. 1.5 times that value below Q1 is 139 - 1.5·48 = 67. Both 59 and 63 could be considered outliers by this criterion.
1.5 times the IQR above Q3 is 187 +1.5·48 = 259. No data values are above that.
The outliers are 59 and 63.
