Let's see...the worst I've been I'm not really sure, because the sickest I have been was in 1990 when I was in college (second worst pfts in the entire Children's clinic, according to my doctor, who was hacked off at me, needless to say), but I don't know the numbers. After that, I went back up into the low 80s (1992) while in the Pulmozyme drug study.
The worst I have been in the last 4 years was Sept. of '04, and my Fev1 was 35% (1.09 liters) and my FVC was 45% (1.51) and I went in the "clink".
Last year about this time, my fev1 was 47% (1.23) and fvc was 62% (2.04) (pretty much my baseline for the last 4 years), and last 2 clinic visits my fev1 was 56% (1.43) and my fvc was 77% (2.51).