-  raw_data.relays.forEach(function(r, i) {
-    if (typeof r.read_history === 'undefined' || typeof r.write_history === 'undefined') {
-      raw_data.relays.splice(i, 1);
-    }
+  raw_data.relays = raw_data.relays.filter(function(r) {
+    return typeof r.read_history !== 'undefined' && typeof r.write_history !== 'undefined';