Median

The 50th percentile or midpoint in a numerically sorted set of continuous (a.k.a. variable or numerical) values. If there are an even number of values in the dataset, it takes the average of the middle two values. It is considered the ideal measure of central tendency for non-normal distributions. It is represented as the Greek letter η pronounced "eta".
Related StatStuff Video: 
   -Section 5-Measure Phase, Lesson #11 - Central Tendency