diff --git a/charting/Months.pm b/charting/Months.pm
new file mode 100755
index 00000000..31a11175
--- /dev/null
+++ b/charting/Months.pm
@@ -0,0 +1,19 @@
+#!/usr/bin/perl -w
+
+#
+# Months.pm
+#
+use File::stat;
+
+@months = (
+	'2006-12',
+	'2007-01', '2007-02', '2007-03', '2007-04', '2007-05', '2007-06',
+	'2007-07', '2007-08', '2007-09', '2007-10', '2007-11', '2007-12',
+	'2008-01', '2008-02', '2008-03', '2008-04', '2008-05', '2008-06',
+	'2008-07', '2008-08', '2008-09', '2008-10', '2008-11', '2008-12',
+	'2009-01', '2009-02', '2009-03', '2009-04', '2009-05', '2009-06',
+	'2009-07', '2009-08', '2009-09', '2009-10', '2009-11', '2009-12',
+	'2010-01',
+);
+
+1;
diff --git a/charting/fetch.pl b/charting/fetch.pl
index 47fbe8b5..2dac9738 100755
--- a/charting/fetch.pl
+++ b/charting/fetch.pl
@@ -4,25 +4,25 @@
 # fetch.pl
 #
 use File::stat;
+use Months;
 
 $fn = '../xml/ukfederation-metadata.xml';
 $fn2 = '../xml/ukfederation-stats.html';
 
-@months = (
-	'2006-12',
-	'2007-01', '2007-02', '2007-03', '2007-04', '2007-05', '2007-06',
-	'2007-07', '2007-08', '2007-09', '2007-10', '2007-11', '2007-12',
-	'2008-01', '2008-02', '2008-03', '2008-04', '2008-05', '2008-06',
-	'2008-07', '2008-08', '2008-09', '2008-10', '2008-11', '2008-12',
-	'2009-01', '2009-02', '2009-03', '2009-04', '2009-05', '2009-06',
-	'2009-07', '2009-08', '2009-09', '2009-10', '2009-11', '2009-12',
-);
-
 foreach $month (@months) {
 	print "Fetching $month...";
-	system("svn update $fn --quiet --revision \\{$month-01T00:00:00Z\\}");
-	system("cp $fn cache/$month.xml");
-	system("svn update $fn2 --quiet --revision \\{$month-01T00:00:00Z\\}");
-	system("cp $fn2 cache/$month.html");
+	
+	my $dest1 = "cache/$month.xml";
+	if (!-e $dest1) {
+		system("svn update $fn --quiet --revision \\{$month-01T00:00:00Z\\}");
+		system("cp $fn $dest1");
+	}
+	
+	my $dest2 = "cache/$month.html";
+	if (!-e $dest2) {
+		system("svn update $fn2 --quiet --revision \\{$month-01T00:00:00Z\\}");
+		system("cp $fn2 $dest2");
+	}
+	
 	print "\n";
 }
diff --git a/charting/saml2.pl b/charting/saml2.pl
index 4b590f6a..dbc61908 100755
--- a/charting/saml2.pl
+++ b/charting/saml2.pl
@@ -7,16 +7,7 @@
 #
 use lib "../build";
 use Xalan;
-
-@months = (
-	'2006-12',
-	'2007-01', '2007-02', '2007-03', '2007-04', '2007-05', '2007-06',
-	'2007-07', '2007-08', '2007-09', '2007-10', '2007-11', '2007-12',
-	'2008-01', '2008-02', '2008-03', '2008-04', '2008-05', '2008-06',
-	'2008-07', '2008-08', '2008-09', '2008-10', '2008-11', '2008-12',
-	'2009-01', '2009-02', '2009-03', '2009-04', '2009-05', '2009-06',
-	'2009-07', '2009-08', '2009-09', '2009-10', '2009-11', '2009-12',
-);
+use Months;
 
 # ingest files
 foreach $month (@months) {
diff --git a/charting/sizes.pl b/charting/sizes.pl
index 0b9d9be6..fd5ed7ac 100755
--- a/charting/sizes.pl
+++ b/charting/sizes.pl
@@ -4,16 +4,7 @@
 # sizes.pl
 #
 use File::stat;
-
-@months = (
-	'2006-12',
-	'2007-01', '2007-02', '2007-03', '2007-04', '2007-05', '2007-06',
-	'2007-07', '2007-08', '2007-09', '2007-10', '2007-11', '2007-12',
-	'2008-01', '2008-02', '2008-03', '2008-04', '2008-05', '2008-06',
-	'2008-07', '2008-08', '2008-09', '2008-10', '2008-11', '2008-12',
-	'2009-01', '2009-02', '2009-03', '2009-04', '2009-05', '2009-06',
-	'2009-07', '2009-08', '2009-09', '2009-10', '2009-11', '2009-12',
-);
+use Months;
 
 # ingest files
 foreach $month (@months) {