Create database table using Drupal hook_schema()

For the last few hours I have been trying to create database table in my custom module with no luck!! The documentation says that you only need to implement hook_schema in Drupal 7 and the Drupal takes care of creating the table during module installation. I just cant figure out why the table is not created. I tried installing the module through Drupal admin as well as pasting in the module folder but it still doesnt work.

Here is my function inside .install file:

/**
 * @return array an array containing table's field definitions
 * to be created by drupal schema api
 */
function inquiry_form_schema() {

  $schema['inquiry_form'] = array(
    'description' => 'Table to record inquiries submitted by staff',
    'fields' => array(
      'ID' => array(
        'description' => 'The primary key of the table',
        'type' => 'serial',
        'size' => 'big',
        'not null' => TRUE,
      ),
      'sender' => array(
        'description' => 'The person who submits the inquiry',
        'type' => 'varchar',
        'length' => '100',
        'not null' => TRUE,
      ),
      'subject' => array(
        'description' => 'Title of the inquiry being submitted',
        'type' => 'char',
        'length' => '100',
        'not null' => TRUE,
      ),
      'department' => array(
        'description' => 'The department that the inquiry is being referenced to',
        'type' => 'varchar',
        'length' => '100',
        'not null' => TRUE,
      ),
      'description' => array(
        'description' => 'Detailed explanation of the issue the sender is experiencing',
        'type' => 'text',
        'not null' => TRUE,
      ),
//      'date' => array(
//        'description' => 'Date of the inquiry being submitted',
//        'mysql_type' => 'datetime',
//        'not null' => TRUE,
//      ),
    ),
    'primary key' => array('ID'),
  );

  return $schema;
}