Report doesn't appear to report all floors

[LoringTupper]

I have a CGA rule that extrudes the building and then splits it into the ground floor that has a height of 5M and the remainder are upper flooors that have a height of 4M. The rule then goes on to report the GFA and FAR but in both of those the number of floors appears to be 1 less than the total, I believe it is because the last split was for the upper floors and the ground floor is being ignored. How do I get the report to include all of the floors?

The CGA code is below:

attr FSetback = 1.5
attr BSetback = 5
attr LSetback = 5
attr RSetback = 5
attr height = 46
attr LUColor = "#ff6464"
attr GroundFloorHeight = 5
attr UpperFloorHeight = 4

@Hidden
attr plotArea = 0 # used to calc FAR

@StartRule
Lot --> setback(FSetback) { street.front : Concrete | remainder : Sub1 }
    
Concrete --> color("#CCCCCC")   #Grey

Sub1 --> setback(BSetback) { street.back : Concrete1 | remainder : Sub2 }

Concrete1 --> color("#CCCCCC")  #Grey

Sub2 --> setback(LSetback) { street.left : Concrete2 | remainder : Sub3 }

Concrete2 --> color("#CCCCCC")  #Grey

Sub3 --> setback(RSetback) { street.right : Concrete3 | remainder : Building }

Concrete3 --> color("#CCCCCC")  #Grey

Building --> extrude(world.y,height)
color(LUColor)
set(plotArea, geometry.area)
BuildingVolume3D

BuildingVolume3D -->
# the 3d volume will not be split into smaller 3d volumes ! 1 ground floor volume will be created.
split(y) {GroundFloorHeight : Volume("GF") | ~1 : AllUpperFloors}

AllUpperFloors -->
# the rest of the volume is not split into upper floor volumes, as many times as possible ('*' sign)
split(y) {~UpperFloorHeight : Volume("UF")}*

Volume(volumeType) -->
case volumeType == "GF" :
  color ("#646464")
else :
   color (LUColor)

set(material.opacity,0.6) FloorCalc

FloorCalc -->
report("GFA",geometry.area)
report("FAR",geometry.area/plotArea)

[LoringTupper]

Thanks for the response Mattias, the code works perfectly but the real gem was the video, it was very valuable in getting to know some of the flow of CGA and how the various rules work together, some things just became clearer while I was watching it.
Sorry for my slow reply, other project pushed me away from CityEngine for a while but I was glad to get back at it and try out the code you supplied and experiment with the insites I learned from the video.
Thanks again.