The average time it takes for Neil to put out an album of all new material is 30 months. Neil generally releases *something* every 20 months (new album, live album, rarities collection, etc.).
It's been 27 months since Neil released Dizzy Heights, so we are overdue for something this year (probably the box set). The longest time Neil has gone without releasing anything was 36 months between Temple of Low Men and Woodface. The second longest time was between Pajama Club and Dizzy Heights at 29 months.
The longest time Neil has gone between proper album releases of all new materials is 41 months between One Nil and Everyone is Here, but he filled that gap by releasing One All and the 7 World Collide live album.
Both Pajama Club (15 months) and Dizzy Heights (29 months) were released sooner than the average of 30 months. In order to continue to beat his average, he would need to release a new album in July, which would be 29 months from the release of Dizzy Heights. That doesn't seem likely.
So, aside from Pajama Club, there is little to signal that Neil is picking up the pace. I guess he's working on two albums at once right now though. If they both come out before the end of 2017 that would be a feat. Then we could see a new Crowded House album between January and June 2020. That's my prediction.
If he doesn't release an album of new material by August 2017 it will be the longest he has ever gone between releases of new material.