Only SH are relevant here, and the figures include the grey Merlins, Lynxes, etc, SAR aircraft and trainers.
They are not inventory of SH figures.
And as someone said, Forward Fleet (defined as aircraft which are serviceable and those which are short term unserviceable - eg aircraft undergoing minor works, forward maintenance or unforeseen rectification work) is more useful.
And more useful still is the fit for purpose figure - eg those aircraft that are serviceable and available to JHC for operational and training purposes. The Fit for Purpose figure varies from day to day, but is always (obviously) less than the Forward figure
I don't have a Commando SK4/6CR set of figures, but the figures below were publicly released.
Inventory Forward
Chinook HC2/A: 40 29
Merlin HC3/3A: 28 19
Puma: 34 25
What this means is that 10 of 29 (not 40) Chinooks are in Helmand, and that 8 more are to be sent!
8 of 19 Merlins are to be sent to Helmand.
These aren't bad percentages of the Forward Fleet.
The problems are that:
1) Forward Fleets are too small
2) We don't have enough SH that would actually be useful in Afghanistan