# set terminal svg size 600,400 dynamic enhanced fname 'arial'  fsize 10 mousing name "histograms_1" butt solid 
# set output 'histograms.1.svg'
set key inside right top vertical Right noreverse noenhanced autotitles nobox
set datafile missing '-'
set style data linespoints
set xtics border in scale 1,0.5 nomirror rotate by -45  offset character 0, 0, 0 autojustify
set xtics  norangelimit font ",8"
set xtics   ()
set title "US immigration from Europe by decade" 
i = 22
plot 'immigration.dat' using 2:xtic(1) title columnheader(2), for [i=3:22] '' using i title columnheader(i)