The median is the middle value, when these are put in order:
 20, 25, 29, 36
In this case, since there's an even number of values, it's the average of the two middle values:
 (25+29)/2 = 27
Median: 27
The mode is the most frequent value:
 three 0s
 five 1s
 two 2s
 one 3
 one 4
Median: 1