In awk, how can I do this:

Input:

1  a  f  1  12  v  
2  b  g  2  10  w  
3  c  h  3  19  x  
4  d  i  4  15  y  
5  e  j  5  11  z  

Desired output, by sorting numerical value at $5:

1  a  f  2  10  w  
2  b  g  5  11  z  
3  c  h  1  12  v  
4  d  i  4  15  y  
5  e  j  3  19  x  

Note that the sorting should only affecting $4, $5, and $6 (based on value of $5), in which the previous part of table remains intact.