--- a
+++ b/benchmark/nctid2patientnumber_startdate.py
@@ -0,0 +1,32 @@
+data_file = "data/raw_data.csv"
+import csv, os, pickle  
+from tqdm import tqdm 
+from xml.etree import ElementTree as ET
+raw_folder = "raw_data"
+
+
+def xmlfile_2_startyear(xml_file):
+	tree = ET.parse(xml_file)
+	root = tree.getroot()
+	try:
+		start_date = root.find('start_date').text	
+		start_date = int(start_date.split()[-1])
+	except:
+		start_date = -1
+	return start_date
+
+
+year_lst = []
+with open(data_file) as f:
+	reader = list(csv.reader(f))[1:]
+	for line in tqdm(reader):
+		nctid = line[0]
+		file = os.path.join(raw_folder, nctid[:7]+"xxxx/"+nctid+".xml")
+		assert os.path.exists(file)
+		start_year = xmlfile_2_startyear(file)
+		if start_year != -1:
+			year_lst.append(start_year)
+
+
+
+