Monitors are not counted as a 'licensed asset', but all the rest does.
This report shows you which asset types are eating your license:
Select Top 1000000 tsysAssetTypes.AssetTypename,
  Count(tblAssets.AssetID) As Total,
  tblState.Statename
From tblAssets
  Inner Join tblAssetCustom On tblAssets.AssetID = tblAssetCustom.AssetID
  Inner Join tsysAssetTypes On tblAssets.Assettype = tsysAssetTypes.AssetType
  Inner Join tblState On tblState.State = tblAssetCustom.State
Where tsysAssetTypes.AssetTypename Not Like 'Monitor'
Group By tsysAssetTypes.AssetTypename,
  tblState.Statename
Order By tsysAssetTypes.AssetTypename,
  tblState.Statename,
  Total Desc