The 2021 SERF Index The 2021 SERF Index Update is now an outdated version of the SERF Index.  The data files are provided here for the convenience of researchers who may be currently using these older versions of the data.  The 2021 SERF Index Update provides SERF Index scores for 12 separate years; 2007 through … Continue reading 2021 International SERF Index Update Downloads