firme	produit	nb
a	1	151.00
a	1	135.00
a	1	137.00
a	2	118.00
a	2	132.00
a	2	135.00
b	1	140.00
b	1	152.00
b	1	133.00
b	2	151.00
b	2	132.00
b	2	139.00
c	1	96.00
c	1	108.00
c	1	94.00
c	2	84.00
c	2	87.00
c	2	82.00
d	1	79.00
d	1	74.00
d	1	73.00
d	2	67.00
d	2	78.00
d	2	63.00