Usage of "since" here

Solution 1:

This is one feature of journalese (a style of writing used mostly in newspapers). Reports and especially headlines are reported in present tense even though they happened in the past.

Example

Suppose a dog has been bitten by a man. In normal language, we might report this as, A dog has been bitten by a man!

As a newspaper headline, it would be Man bites dog!

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