PHP Inserting multiple rows into database

PHP Inserting multiple rows into database

i have a <?php include 'stats.php'; ?> on every page on my site. in the
stats.php file there is a SQL Insert query that inserts data into a table
in my database.
for some reason when visiting just one page it inserts 4 rows into the
database - there is only one SQL Command.
why would it be doing this... below is ALL the code on the stats.php file
<?php
$activity_history_sql=
"INSERT into user_activity_history (user_seq, user, timestamp,
ip_address, user_request_uri,
user_script_filename, user_script_uri, user_script_url,
user_script_name, user_php_self)
values ('".$_SESSION["integradigital.co.uk"]["sequence"]."',
'".$_SESSION["integradigital.co.uk"]["forename"].'
'.$_SESSION["integradigital.co.uk"]["surname"]."',
'".date("Y-m-d H:i:s")."',
'".$_SERVER["REMOTE_ADDR"]."',
'".$_SERVER["REQUEST_URI"]."',
'".$_SERVER["SCRIPT_FILENAME"]."',
'".$_SERVER["SCRIPT_URI"]."',
'".$_SERVER["SCRIPT_URL"]."',
'".$_SERVER["SCRIPT_NAME"]."',
'".$_SERVER["PHP_SELF"]."') ";
$activity_history_rs=mysql_query($activity_history_sql,$conn) or
die(mysql_error());
?>