Missing SLC Data New Zealand 2016-2017

I’m working with Sentinel1 SLC data in New Zealand and I’ve notice there is a year-long data gap. Specifically, between June 2017 and 2018, along relative orbit 73, using the search criteria:

( footprint:"Intersects(POINT(175.14 -39.83))" ) AND ( beginPosition:[2017-06-01T00:00:00.000Z TO 2018-06-01T23:59:59.999Z] AND endPosition:[2017-06-01T00:00:00.000Z TO 2018-06-01T23:59:59.999Z] ) AND ( (platformname:Sentinel-1 AND producttype:SLC AND sensoroperationalmode:IW AND relativeorbitnumber:73))

There is only on image available. Does anyone know why this gap exists? Have others had similar issues? Is there any chance that this data is available somewhere? Any insight or advice would be appreciated.