Add self-computed IF to SciPost Physics footer

journals/templates/journals/base.html

@@ -40,11 +40,20 @@
         <div class="row my-1">
             <div class="col-12">
                 {% if journal.active %}
-                    <p>{{journal}} is published by the SciPost Foundation under the journal doi: 10.21468/{{journal.name}}{% if journal.issn %} and ISSN {{journal.issn}}{% endif %}.</p>
+                <p>{{journal}} is published by the SciPost Foundation under the journal doi: 10.21468/{{journal.name}}{% if journal.issn %} and ISSN {{journal.issn}}{% endif %}.</p>
                 {% endif %}
 		{% if journal.doi_label == 'SciPostPhys' %}
-		    <p>SciPost Physics has been awarded the DOAJ Seal <img src="{% static 'scipost/images/DOAJ_Seal_logo_big.png' %}" alt="DOAJ Seal" width="40"> from the <a href="https://doaj.org">Directory of Open Access Journals</a></p>
-    		<p class="mb-0">All content in {{ journal }} is deposited and permanently preserved in the CLOCKSS archive <a href="https://www.clockss.org/clockss/Home" target="_blank"><img src="{% static 'scipost/images/clockss_original_logo_boxed_ai-cropped-90.png' %}" alt="CLOCKSS logo" width="40"></a></p>
+		<p class="mb-1">
+		  SciPost Physics has been awarded the DOAJ Seal <img src="{% static 'scipost/images/DOAJ_Seal_logo_big.png' %}" alt="DOAJ Seal" width="40"> from the <a href="https://doaj.org">Directory of Open Access Journals</a>
+		</p>
+		<p>
+		  All content in {{ journal }} is deposited and permanently preserved in the CLOCKSS archive <a href="https://www.clockss.org/clockss/Home" target="_blank"><img src="{% static 'scipost/images/clockss_original_logo_boxed_ai-cropped-90.png' %}" alt="CLOCKSS logo" width="40"></a>
+		</p>
+    		<p class="mb-1">
+		  Self-computed impact factor
+		  <small><sup><i class="fa fa-question-circle" data-toggle="tooltip" data-html="true" title="Number of citations in year N for papers published in years N-1 and N-2,<br/>divided by the number of papers in those years.<br/>Data obtained from Crossref's Cited-by service"></i></sup></small> for 2018		  (using <a href="https://www.crossref.org/services/cited-by/" target="_blank">Crossref Cited-by</a> data)
+: <strong>5.25</strong>
+		</p>
 		{% endif %}
 	    </div>
         </div>