GSP min support value

I am trying to understand how to interpret min support for the GSP operator.

Is min support computed based on the number of customers (so is the denominator of min support = # customers) or something else?
When using the dataset below with a min support < 0.5, I would expect no sequences to be generated.

Instead, GSP appears to generate thousands of sequences. I actually stop the process before it completes...

Any insight would be appreciated.
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ID,Time,Item1,Item2,Item3,Item4,Item5,Item6
1,10.0,yes,yes,no,no,no,no
1,25.0,no,no,no,yes,yes,no
1,40.0,no,no,yes,no,no,no
1,50.0,yes,no,no,no,no,no
1,51.0,no,yes,no,no,no,no
1,65.0,no,no,yes,no,no,no
1,90.0,no,yes,no,yes,no,no
1,96.0,no,no,no,no,yes,no
2,5.0,no,yes,no,yes,yes,no
2,15.0,no,no,no,yes,yes,no
2,35.0,no,no,yes,no,no,no
2,50.0,yes,no,no,no,no,no
2,64.0,no,yes,no,no,no,no
2,65.0,no,no,yes,no,no,no
2,89.0,no,yes,no,yes,no,no
2,95.0,yes,yes,yes,no,no,no
2,105.0,no,no,no,yes,yes,no
2,106.0,yes,yes,no,no,no,no
2,130.0,no,no,no,yes,no,no
2,140.0,no,no,no,no,no,yes