Thought this analysis might be of interst:
For the overall strengths of the whole air force, including those elements not actively engaged in the battle, Ellis gives the following Monthly subtotals.
Explanation: XX/YY = RAF/LW
August 1940: 2913/3015
December1940: 2916/2805
June 1941: 3106/3451
Ellis gives the following information with regards to serviceable strengths for both the RAF and the LFs 2 3 of the Lufwaffe at selected dates
July 6 1940
SE Fighters: 644 /760*
TE Fighters: (?)/220*
Ground Attack: (?)/280*
Level Bombers: (?)/1200*
*: At this date serviceability was only about 50% of the figures given, due to the state of the airfields in Northern France.
July 20 1940:
SE Fighters: 658 /656
TE Fighters: (?)/168
Ground Attack: (?)/261
Level Bombers: (?)/998
August 10 1940:
SE Fighters: 749 /805
TE Fighters: (?)/224
Ground Attack: (?)/261
Level Bombers: (?)/998
September 07 1940:
SE Fighters: 746 /623
TE Fighters: (?)/129
Ground Attack: (?)/180
Level Bombers: (?)/772
September 28 1940:
SE Fighters: 732 /275
TE Fighters: (?)/230
Ground Attack: (?)/276
Level Bombers: (?)/750
Deighton confirms the catastrophic loss in serviceability for Me109s. He lists the serviceability of the JGs as 238 as of early October.
Ellis provides further figures on the whole of the Luftwaffe at selected dates. These numbers are totals, but don't include reserves (if there were any):
June 1940: 1107 (SE) F, 357 (TE)F, 453 Ground Attack, 1380 Bombers, 357 Trans
September 1940: 932 (SE) F, 181 (TE)F, 483 Ground Attack, 1420 Bombers, 365 Trans
December 1940: 832 (SE) F, 241 (TE)F, 482 Ground Attack, 1330 Bombers, 415 Trans
With regards to numbers of sorties flown and bomb tonnages dropped, the Luftwaffe showed a dramatic loss of efficiency:
Sorties/tons dropped
Sept: 7260/7044, Oct: 9911/9113, Nov (c) 6000/6510, Dec 3844/4323
With regard to outright losses, Ellis provides the following statistics. Numbers in brackets show non combat losses (accidents mostly) where available, and included in the totals:
RAF: Fighter/Other, Luftwaffe SE fighter/TE Fighter/Ju87/Bomber/Other
10-30 July RAF: 75(27)/8(1), LW: 40(2)/9(3)/8(2)/108(29)/6(1)
31 July to 27 August: RAF: 284(30)/30(7), LW: 160(29)/108(6)/58(2)/248(51)/21(9)
28 August to 01 October: RAF: 471(32)/12(5), LW: 300(35)/100(6)/10(10)/335(68)/28(18)
02 October to 31 October:RAF: 174(57)/11(7), LW: 136(24)/26(12)/4(4)/190(64)/19(9)
In that period, the following se fighters were delivered to the RAF/LW
June: 446/164, July 496/220, Aug 476/173, Sept 467/218, Oct 469/144
Just comparing losses to additions, I calculate the Luftwaffe to have undergone the following changes to its SE Fighter OB in that July/October period
July: +180, August: +13, Sep -82, Oct +8
Overall, its true that more aircraft joined the LW than were lost, however this does not translate to a corresponding increase in frontline/operational strengths for the Fighter arm And we have not looked at what happened to the other types in Luftwaffe service. Compared to the net increases occurring in the RAF including reserves, Luftwaffe gains in numbers were trifling, and when serviceability rates were considered, losses were catastrophic.