try this
Step 3.
Open /lang/<yourlanguage>/main.php
At the end of the file, just before closing ?> add this:
//-----------------------------------------------------
//--- Search Statistics -------------------------------
//-----------------------------------------------------
$lang['search_stats'] = "Search Statistic";
$lang['search_stats_words'] = "Words";
$lang['search_stats_phrases'] = "Phrases";
$lang['search_stats_paging'] = "Found {words} words(s) and {phrases} phrase(s) on {total_pages} page(s).";
$lang['search_stats_sort'] = "Sort stats by:";
$lang['search_stats_perpage'] = "Per page:";
$lang['search_stats_nowords'] = "No words were found";
$lang['search_stats_nophrases'] = "No phrases were found";
$lang['search_stats_date_alt'] = "Date of last search";
$lang['search_stats_sort_options'] = array(
"text" => "Alphabet",
"count" => "Count",
"date" => "Date",
"guests" => "Guests",
"users" => "Users",
"admins" => "Admins"
);
$lang['search_stats_order_options'] = array(
"ASC" => "Ascending",
"DESC" => "Descending"
);
//--- End Search Statistics ---------------------------