"nop-hist.txt" with lp lt 1 title "No modifications", \
"mod-hist.txt" with lp lt 2 title "Two modifications", \
"mod2-hist.txt" with lp lt 3 title "Four modifications", \
"nop-hist.txt" with lp lt 1 title "No modifications", \
"mod-hist.txt" with lp lt 2 title "Two modifications", \
"mod2-hist.txt" with lp lt 3 title "Four modifications", \