I want to know the frequency of CNV events for all genes in breast cancer using COSMIC data. For this purpose, COSMIC generates a nice tabular format based on given filters like type of cancer etc (see http://cancer-beta.sanger.ac.uk/cosmic/browse/tissue#sn=breast&ss=all&hn=all&sh=all&in=t&src=tissue&all_data=n&wgs=off). The table can be viewed in Variants -> CNV & Expression tab in "Cosmic » Cancer Browser » Breast" section.
I realized that sometimes the above table contains multiple entries for the same gene. For instance, for ERBB2, it shows 7 entries, as given in the this link https://ibb.co/doK5iQ
My question is which entry one can use for computing the frequency of gains and losses in this case?