gistfile1.txt

command		1979	1996	2015	2017	OpenBSD		9front
ls		11	42	58	58	28		13
rm		3	7	11	12	7		2
mkdir		0	4	6	7	2		2
mv		0	9	13	14	3		0
cp		0	18	30	32	9		3
cat		1	12	12	12	7		0
pwd		0	2	4	4	2		0
chmod		0	6	9	9	5		0
echo		1	4	5	5	1		1
man		5	16	39	40	12		7
which			0	1	1	1		n/a
sudo			0	23	25	n/a		n/a
tar		12	53	134	139	33		17
touch		1	9	11	11	6		2
clear			0	0	0	1		n/a
find		14	57	82	82	44		n/a
ln		0	11	15	16	6		n/a
ps		4	22	85	85	26		4
ping			12	12	29	21		10
kill		1	3	3	3	2		0
chown		0	6	15	15	5		n/a
grep		11	22	45	45	33		11
tail		1	7	12	13	5		5
df		0	10	17	18	7		n/a
top			6	12	14	16		n/a