(meteorobs) Geminid bonanza in Colorado

[Roberto Gorelli]

On Sat, 14 Dec 2013 13:29:38 -0700
  Chris Peterson <clp at alumni.caltech.edu> wrote:
> My video camera has recorded the following from Colorado over the 
>last 
> four nights:
> 
> Andromedid 10
> Puppid-Velid 18
> Monocerotid 31
> chi Orionid 5
> sigma Hydrid 24
> Geminid 327
> 46P 16
> Sporadic 45
> Unknown 22
> 
> Total meteors: 498
> 
> 171 Geminids last night, with a few hours of cloudiness cutting the 
> count a little.
> 
> Composite images, activity plot, and fireball videos are at 
> http://www.cloudbait.com/science/geminid2013.html
> 
> Chris

What it's the difference between Sporadic and Unknown?
Best greetings.
Roberto Gorelli