Loop through all posts in a certain year

You will have to run a custom query for that. Here is the query for displaying posts from a particular year. I have used year 2012 as an example.

$args = array(
  'post_type' => 'post',
  'ignore_sticky_posts' => 1,
  'year'  => '2012',
);

$the_query = new WP_Query( $args );

if ( $the_query->have_posts() ) :
  while ( $the_query->have_posts() ) : $the_query->the_post();

      the_content();

  endwhile;
endif;

wp_reset_postdata();