diff --git a/rrd/rrd.go b/rrd/rrd.go
index 160166f..725f302 100644
--- a/rrd/rrd.go
+++ b/rrd/rrd.go
@@ -13,12 +13,14 @@ import (
 
 var linePattern = regexp.MustCompile("^<!-- ....-..-.. ..:..:.. [A-Z]+ / (\\d+) --> <row><v>([^<]+)</v><v>([^<]+)</v></row>")
 
+// Dataset a timestemp with values (node and clients)
 type Dataset struct {
 	Time    time.Time
 	Nodes   float64
 	Clients float64
 }
 
+// Read a rrdfile and return a chanel of datasets
 func Read(rrdFile string) chan Dataset {
 	out := make(chan Dataset)
 	cmd := exec.Command("rrdtool", "dump", rrdFile)
@@ -48,10 +50,10 @@ func Read(rrdFile string) chan Dataset {
 				found = strings.Contains(str, "<!-- 86400 seconds -->")
 				continue
 			}
-			if matches := linePattern.FindStringSubmatch(str); matches != nil && matches[2] != "NaN" {
+			if matches := linePattern.FindStringSubmatch(str); matches != nil && matches[2] != "NaN" && matches[3] != "NaN" {
 				seconds, _ := strconv.Atoi(matches[1])
 				nodes, _ := strconv.ParseFloat(matches[2], 64)
-				clients, _ := strconv.ParseFloat(matches[2], 64)
+				clients, _ := strconv.ParseFloat(matches[3], 64)
 
 				out <- Dataset{
 					Time:    time.Unix(int64(seconds), 0),