diff --git a/p9/data/ferro/20.dat b/p9/data/ferro/20.dat
new file mode 100644
index 0000000..a468320
--- /dev/null
+++ b/p9/data/ferro/20.dat
@@ -0,0 +1,10 @@
+590	0.81	21.429	0.667
+1120	0.89	23.509	0.712
+1300	0.91	24.028	0.723
+1570	0.94	24.806	0.741
+1880	1.02	26.876	0.787
+2285	0.99	26.100	0.769
+2720	1.06	27.908	0.811
+3190	1.03	27.134	0.793
+3510	1.05	27.650	0.805
+3970	1.04	27.392	0.799