I think the similarity between the 17 and 5 year averages probably isn't meaningful. Attached is the spreadsheet link. You can randomly pick other weeks and see if the long and short terms averages are as close as this week's appear to be. Probably not.

Since, according to EIA, the "storage week" is calculated every Friday, to get an average injection figure for the last week of June, requires that you pick a Friday that occurs during the last week of June. This year it was the 24th. It could be anywhere from the 23rd to the 30th, though, so there isn't a perfect match between the real calendar and the storage week. Hope this helps. CJ