My lineage has actually been "linear" since 1996-1997. I think we are actually the only lineage remaining that is still linear and I think that's special
Our family has only ever taken one littler per big. My little deactivated (sadness, but she was closer with another circle of friends outside the sorority, never lived in the house, etc.), so my lineage actually got SMALLER! Of course I have an unofficial "pseudo-little," and a fake adopted little after her big who was two years older than she graduated, but they are auxiliary littles not really in my lineage.
After I graduated in May, only 2 members in my lineage remain at school. BUT, my little little little (great grandlittle) is awesome and I know she will get a really involved little to keep our family alive!