Postgres individual inserts slow performance

#! /usr/bin/env python

import psycopg2
import time

conn = psycopg2.connect('dbname=refillrx')
cur = conn.cursor()

cur.execute('DROP TABLE header')
cur.execute(' CREATE TABLE header( phone CHAR(10) )')

for i in range(8):

    t1 = time.time()
    cur.execute("INSERT INTO header(phone) VALUES('1112223333')")
    conn.commit()
    print 'Elapsed: %.4f sec' % (time.time() - t1)

    time.sleep(0.2)  # Sleep 0.2 sec

'''
Output:

Elapsed: 0.0116 sec
Elapsed: 0.2018 sec
Elapsed: 0.1982 sec
Elapsed: 0.0019 sec
Elapsed: 0.0030 sec
Elapsed: 0.1945 sec
Elapsed: 0.0017 sec
Elapsed: 0.0013 sec

'''