How do I change all locations to cities on home page

<div id="home-regs">
    <h2><?php _e('All locations', 'sigma'); ?></h2>

    <div class="wrap">
      <?php $regions = RegionStats::newInstance()->listRegions('%%%%', '>', 'i_num_items DESC'); ?>

      <?php $i = 1; ?>
      <?php foreach($regions as $r) { ?>
        <?php if($i <= 20) { ?>
          <div><a href="<?php echo osc_search_url(array('page' => 'search', 'sRegion' => $r['pk_i_id']));?>"><i class="fas fa-location-arrow"></i> <span><?php echo $r['s_name']; ?></span> <em>(<?php echo $r['i_num_items']; ?>)</em></a></div>
          <?php $i++; ?>
        <?php } ?>
      <?php } ?>

@mheston
Try this:
  <div id="home-regs">
    <h2><?php _e('All locations', 'sigma'); ?></h2>

    <div class="wrap">
      <?php $cities = CityStats::newInstance()->listCities('%%%%', '>', 'i_num_items DESC'); ?>

      <?php $i = 1; ?>
      <?php foreach($cities as $c) { ?>
        <?php if($i <= 20) { ?>
          <div><a href="<?php echo osc_search_url(array('page' => 'search', 'sCity' => $c['city_id']));?>"><i class="fas fa-location-arrow"></i> <span><?php echo $c['city_name']; ?></span> <em>(<?php echo $c['items']; ?>)</em></a></div>
          <?php $i++; ?>
        <?php } ?>
      <?php } ?>

    </div>
  </div>

Thank you very much for the help. I think it shows the region when the region has a listing, how would I show all regions even if there is no listing. for example,

 Texas (0)
 California (0)
 Ohio (0)
 
 would this be the code that would need changed
 
 <?php if($i <= 20) { ?>
 
 and thanks for the tip about the cache plugin, I purchased it and it works great.

@mheston
You must develop it, I do not have code for that 
Require usage of different functions.

Maybe if you change this:
      <?php $cities = CityStats::newInstance()->listCities('%%%%', '>', 'i_num_items DESC'); ?>

Into this:
      <?php $cities = CityStats::newInstance()->listCities('%%%%', '>=', 'i_num_items DESC'); ?>

it could work as well.

this code you shared with me worked great for regions and cities, can it be modified to show categories.


<div id="home-regs">
    <h2><?php _e('All locations', 'sigma'); ?></h2>

    <div class="wrap">
      <?php $cities = CityStats::newInstance()->listCities('%%%%', '>', 'i_num_items DESC'); ?>

      <?php $i = 1; ?>
      <?php foreach($cities as $c) { ?>
        <?php if($i <= 20) { ?>
          <div><a href="<?php echo osc_search_url(array('page' => 'search', 'sCity' => $c['city_id']));?>"><i class="fas fa-location-arrow"></i> <span><?php echo $c['city_name']; ?></span> <em>(<?php echo $c['items']; ?>)</em></a></div>
          <?php $i++; ?>
        <?php } ?>
      <?php } ?>

    </div>
  </div>