Paging page with users

I have a user page at my site showing nice name and avatar. After 1 week there is already 400 users at the site, and the users page is getting slow to load. How can I paginate the page? Below is the code I use to display the authors:

<?php
						// Get the authors from the database ordered by user nicename
							global $wpdb;
							$query = "SELECT ID, user_nicename from $wpdb->users ORDER BY user_nicename";
							$author_ids = $wpdb->get_results($query);

						// Loop through each author
							foreach($author_ids as $author) :

						// Get user data
							$curauth = get_userdata($author->ID);

						// If user level is above 0 or login name is "admin", display profile
							if($curauth->user_level > 0 || $curauth->user_login == 'admin') :

						// Get link to author page
							$user_link = get_author_posts_url($curauth->ID);

						// Set default avatar (values = default, wavatar, identicon, monsterid)
							$avatar = 'wavatar';

					?>
                    <div class="authorpost overview">
                        <a class="authorimage" href="<?php echo $user_link; ?>" title="<?php echo $curauth->display_name; ?>">
                            <?php echo get_avatar($curauth->user_email, '40'); ?>
                        </a>
                        <?php echo $user_registered ?>
                        <a class="title" href="<?php echo $user_link; ?>" title="<?php echo $curauth->display_name; ?>"><?php echo $curauth->display_name; ?></a><br />

                    </div>
					<?php endif; ?>
					<?php endforeach; ?>