Fama and French's Five Factor Asset Pricing Model

#1
ddd marketcap_q mb
30/12/2015 5 1.2073066
30/12/2015 3 0 .1281925
30/12/2015 4 1.154178
30/12/2015 4 1.154178
30/12/2015 5 1 .2073066
30/12/2015 5 1 .2073066
30/12/2015 5 1 .2073066
30/12/2015 3 0 .1781925
30/12/2015 1 -.6993591
30/12/2015 2 .9836863

I am wondering how I can generate the new variable that is equal to the value of the bottom quantile less that of the top quantile. For ddd=30/12/2015, the value of the new variable must be -.6993591-1.2073066.