I've gathered some figures (I won't call them statistics for obvious reasons) which might make interesting reading.
They cover solos for 1984 to 2002 inclusive.
Make of them what you will.
Number of incidents on
Lap 1 of a 3 lap race = 7
Lap 1 of a 4 lap race = 16
Lap 1 of a 6 lap race = 10
Lap 2 of a 2 lap race = 3
Lap 2 of a 3 lap race = 1
Lap 2 of a 4 lap race = 14
Lap 2 of a 6 lap race = 7
Lap 3 of a 3 lap race = 4
Lap 3 of a 4 lap race = 16
Lap 3 of a 6 lap race = 9
Lap 4 of a 4 lap race = 13
Lap 4 of a 6 lap race = 15
Lap 5 of a 6 lap race = 10
Lap 6 of a 6 lap race = 9
So lap 1 has 33 incidents
Lap 2 has 25
Lap 3 has 29
Lap 4 has 28
Lap 5 has 10
Lap 6 has 9
This doesn't take account of the number of 6 lap races versus the number of 4 lap races and maybe any statisticians out there could come to some conclusions.
The list of locations also makes interesting reading.
I've only included here places with 5 or more incidents( but I have included practice incidents)..
Governors 43 (30 in practice)
Quarter Bridge 29 (20 in practice)
Braddan 21 (17 in practice)
Greeba Castle 14 (9 in practice)
Bungalow 14 (13 in practice)
Laurel bank 14 (10 in practice)
Creg 12 (5 in practice)
Brandywell 11 (8 in practice)
Sulby Bridge 11 (7 in practice)
Guthries 10 (2 in practice)
Cruikshanks 10 (7 in practice)
Nook 9 (5 in practice)
Sarahs 9 (6 in practice)
Waterworks 9 (6 in practice)
Windy Corner 9 (8 in practice)
Parliament Square 9 (7 in practice)
Hairpin 9 (8 in practice)
Ballaugh 8 (7 in practice).
Brandish 8 (7 in practice)
Quarry Bends 8 (2 in practice)
Signpost 8 (6 in practice)
Union Mills 7 (5 in practice )
Kates/Keppel 7 (5 in practice)
Kerrowmoar 7 (6 in practice)
Gooseneck 6 (4 in practice)
Barregarrow 6 (all in practice)
Greeba Bridge 6 (3 in practice)
Whitegates 6 (3 in practice)
Glen Helen 5 (3 in practice)
Start line !!! 3 (all in practice)

There are obviously a number of black spots which could possibly be highlighted to riders, and it is also evident that the majority of incidents take place in practice.
I don't think that the weather or whether it was morning or evening had any major bearing on the number of incidents, though again statisticians could probably make more of it.