lubuntu.me/plugins/wp-statistics/includes/settings/tabs/wps-maintenance.php

<?php
if ( $wps_nonce_valid ) {

	$wps_option_list = array(
		'wps_schedule_dbmaint',
		'wps_schedule_dbmaint_days',
		'wps_schedule_dbmaint_visitor',
		'wps_schedule_dbmaint_visitor_hits',
	);

	foreach ( $wps_option_list as $option ) {
		$new_option = str_replace( "wps_", "", $option );
		if ( array_key_exists( $option, $_POST ) ) {
			$value = $_POST[ $option ];
		} else {
			$value = '';
		}
		$WP_Statistics->store_option( $new_option, $value );
	}
}

?>
    <script type="text/javascript">
        function DBMaintWarning() {
            var checkbox = jQuery('#wps_schedule_dbmaint');

            if (checkbox.attr('checked') == 'checked') {
                if (!confirm('<?php _e( 'This will permanently delete data from the database each day, are you sure you want to enable this option?', 'wp-statistics' ); ?>'))
                    checkbox.attr('checked', false);
            }


        }
    </script>
    <table class="form-table">
        <tbody>
        <tr valign="top">
            <th scope="row" colspan="2"><h3><?php _e( 'Purge Old Data Daily', 'wp-statistics' ); ?></h3></th>
        </tr>

        <tr valign="top">
            <th scope="row">
                <label for="wps_schedule_dbmaint"><?php _e( 'Enabled', 'wp-statistics' ); ?>:</label>
            </th>

            <td>
                <input id="wps_schedule_dbmaint" type="checkbox"
                       name="wps_schedule_dbmaint" <?php echo $WP_Statistics->get_option( 'schedule_dbmaint' ) == true
					? "checked='checked'" : ''; ?> onclick='DBMaintWarning();'>
                <label for="wps_schedule_dbmaint"><?php _e( 'Enable', 'wp-statistics' ); ?></label>

                <p class="description"><?php _e(
						'A WP Cron job will be run daily to purge any data older than a set number of days.',
						'wp-statistics'
					); ?></p>
            </td>
        </tr>

        <tr valign="top">
            <th scope="row">
                <label for="wps_schedule_dbmaint_days"><?php _e( 'Purge data older than', 'wp-statistics' ); ?>:</label>
            </th>

            <td>
                <input type="text" class="small-text code" id="wps_schedule_dbmaint_days"
                       name="wps_schedule_dbmaint_days" value="<?php echo htmlentities(
					$WP_Statistics->get_option( 'schedule_dbmaint_days', "365" ),
					ENT_QUOTES
				); ?>"/>
				<?php _e( 'Days', 'wp-statistics' ); ?>
                <p class="description"><?php echo __(
						'The number of days to keep statistics for.  Minimum value is 30 days.  Invalid values will disable the daily maintenance.',
						'wp-statistics'
					); ?></p>
            </td>
        </tr>

        <tr valign="top">
            <th scope="row" colspan="2"><h3><?php _e( 'Purge High Hit Count Visitors Daily', 'wp-statistics' ); ?></h3>
            </th>
        </tr>

        <tr valign="top">
            <th scope="row">
                <label for="wps_schedule_dbmaint_visitor"><?php _e( 'Enabled', 'wp-statistics' ); ?>:</label>
            </th>

            <td>
                <input id="wps_schedule_dbmaint_visitor" type="checkbox"
                       name="wps_schedule_dbmaint_visitor" <?php echo $WP_Statistics->get_option(
					'schedule_dbmaint_visitor'
				) == true ? "checked='checked'" : ''; ?> onclick='DBMaintWarning();'>
                <label for="wps_schedule_dbmaint_visitor"><?php _e( 'Enable', 'wp-statistics' ); ?></label>

                <p class="description"><?php _e(
						'A WP Cron job will be run daily to purge any users statistics data where the user has more than the defined number of hits in a day (aka they are probably a bot).',
						'wp-statistics'
					); ?></p>
            </td>
        </tr>

        <tr valign="top">
            <th scope="row">
                <label for="wps_schedule_dbmaint_visitor_hits"><?php _e(
						'Purge visitors with more than',
						'wp-statistics'
					); ?>:</label>
            </th>

            <td>
                <input type="text" class="small-text code" id="wps_schedule_dbmaint_visitor_hits"
                       name="wps_schedule_dbmaint_visitor_hits" value="<?php echo htmlentities(
					$WP_Statistics->get_option( 'schedule_dbmaint_visitor_hits', '50' ),
					ENT_QUOTES
				); ?>"/>
				<?php _e( 'Hits', 'wp-statistics' ); ?>
                <p class="description"><?php echo __(
						'The number of hits required to delete the visitor.  Minimum value is 10 hits.  Invalid values will disable the daily maintenance.',
						'wp-statistics'
					); ?></p>
            </td>
        </tr>

        </tbody>
    </table>

<?php submit_button( __( 'Update', 'wp-statistics' ), 'primary', 'submit' );