Raw <- read.table("it.feb.txt", header=TRUE, row.names=1)

ind <- which((Raw==Raw["all",1]) |      ## find row with "all"
             (Raw==Raw["total",1]))     ##          or "total"

Dat <- Raw[-ind,,drop=FALSE]            ## new data.frame without that row
Dat <- Dat[order(-Dat[,1]),1,drop=FALSE]## (re-)order by downloads, desc.
Dat <- rbind(Dat, total=sum(Dat[,1]))   ## add a new row for totals

Dat <- cbind(Dat,                       ## add a percentage column
             percent=round(100*Dat[,1]/Dat["total",1], 4))
Dat <- cbind(Dat,                       ## and one for cumulative percentages
             cumulpct=round(cumsum(Dat[,1]/Dat["total",1]*100), 4))
Dat["total","cumulpct"] <- NA
print(Dat)                              ## show result