add mean score methods
add mean score methods

willmclaren/ensembl-variation,Ensembl/ensembl-variation,willmclaren/ensembl-variation,willmclaren/ensembl-variation,willmclaren/ensembl-variation,Ensembl/ensembl-variation,Ensembl/ensembl-variation,Ensembl/ensembl-variation,Ensembl/ensembl-variation,willmclaren/ensembl-variation