What does this mean - Then knit on foll 6 alt rows, then on every foll 4th row until 83 sts rem.?

I'm knitting a sweater and I'm at the section where I'm shaping the armholes. I've been decreasing for the past 7 rows. The next part of the pattern is telling me to dec 1 st at each end of next 5 rows, (I have done this part), then on foll 6 alt rows, then on every foll 4th row until 83 sts rem. This is where I'm lost. Any help would be appreciated. Pat