else:
                index = int(round(max_heatmap_index * math.log(
                            num_recipients)/math.log(max_recipients)))

            td_attributes = {'class':'heatmap {0}'.format(
                    heatmap_class_for(index))}

            recipients_filename = '{0}-{1}.html'.format(
                    slugify(x_funder), slugify(y_funder))
            a_attributes = {'href' : recipients_filename}

            if num_recipients == 0:
                td_text = num_recipients
            else:
                td_text = html_writer.get_html('a', 
                                               num_recipients, 
                                               a_attributes)
                write_recipients_page(output_dir,
                                      recipients_filename,
                                      x_funder,
                                      y_funder,
                                      recipients)
                
        html_writer.write_html('td', td_text, td_attributes)
    html_writer.close_tag('tr')

html_writer.write_html('th', '')

for funder in x_funders:
    html_writer.write_html('th', funder)