> Ubuntu 17.04 'Zesty Zapus'
As Ubuntu are up to "Z" for 'Zesty Zapus', then this April marks the 26th release of Ubuntu since October 2004. Since then they have rolled-out two releases per year every April and October.
I recollect there was one release that they knew they wouldn't have complete for April and they announced prior to April that they would be a month or two late in releasing.
I consider their project management ability to be an example of excellence for rolling-out so many product releases on schedule. I suspect that their roll-out history would put many commercial software vendors to shame.
cheers,
Ian.