shell script to sort the 5th column

hi folks, I have this data in a data.txt file and i want to sort the 5th column and in descending order:

 Jun 15  119.167.247.40  =  23  Jun 15  119.167.247.40  =  3  Jun 15  208.115.46.125  =  12  Jun 15  208.115.46.125  =  6  Jun 15  210.51.10.160  =  20   

I want this sample output:

   Jun 15  119.167.247.40  =  23  Jun 15  210.51.10.160  =  20  Jun 15  208.115.46.125  =  12  Jun 15  208.115.46.125  =  6  Jun 15  119.167.247.40  =  3   

Thanks for your help..

Try:

xargs -n5 < data.txt | sort -k5rn | xargs

Thanks Scrutinizer,

I got a new problem..
seems not easy to do alignment now when posting with codes or html.

regards