You also posted this over at the fashion spot, but it is really quite hard to tell because Dsquared does numerous leather pants each and every season. I have nothing against leather pants, per se, but these really are hideous.
Anyway, I would guess that perhaps they are from autumn/winter 2004, in which they offered more styles of leather pants even than usual of this general type.
Nevertheless, by doing a little searching on your own at places like www.firstview.com
might answer the question better than we could. These sites all have photos of the runway collections.
You could also try emailing Dsquared via their website. They might know better than anybody.