Group posts by year in loop

How can I separate posts by year in archive page for Custom Post Type?

while ( have_posts() ) : the_post();

the_title();
the_post_thumbnail('thumb'); 

endwhile;

The end result would look something like this:

2016
- Title1
- Title2
- Title3
- Title4

2015
- Title1
- Title2
- Title3
- Title4

etc.

This little snippet could help you.

$years = array();

  if( have_posts() ) {
    while( have_posts() ) {
      the_post();
      $year = get_the_date( 'Y' );
      if ( ! isset( $years[ $year ] ) ) $years[ $year ] = array();
      $years[ $year ][] = array( 'title' => get_the_title(), 'permalink' => get_the_permalink() );
    }
  }

This code gets all posts (in the current loop), gets the year of each post, pushes each post title and permalink to its year array.