You mean post-Troughton, I assume?
It's far more post-Hartnell. There's one historical in Troughton's era, and it's his second story (The Highlanders).
Hartnell stories break down as follows:
* Historicals: 10
* Historical with alien influence: 1 (The Meddling Monk)
* Alien Planet/Future Earth: 16
* Modern Day: 2 (Planet of Giants, War Machines)
Troughton Stories break down as follows:
* Historicals: 1
* Modern Day: 6
* Alien Planet/Future Earth: 14
The Modern Day one is difficult: How do you group "Abominable Snowmen" or "Evil of the Daleks"? In the end, I've gone for Modern Day, as they're not strictly "Historical with alien influences".
Pertwee Stories...
* Historicals: 0
* Historicals with Alien Influences: 1 (Time Warrior)
* Modern Day: 15
* Alien Planet/Future Earth: 8
(Few mixes here: Three Doctors, Time Monster, Day of the Daleks, Planet of the Spiders, which I've lumped into "Modern Day")
Tom Baker Stories...
* Historicals: 0
* Historicals with Alien Influences: 4 (Pyramids of Mars, Talons of Weng-Chiang, Mask of Mandragora, Horror of Fang Rock)
* Modern Day: 8
* Alien Planet/Future Earth: 29
Peter Davison Stories:
* Historicals: 1 (Black Orchid)
* Historicals with Alien Influences: 3 (The Visitation, The Awakening, King's Demons)
* Modern Day: 1 (Mawdryn Undead)
* Other Stuff: 15
I'm using "Other Stuff" due to stories like Arc of Infinity, Four To Doomsday and Time-Flight.
Colin Baker stories:
* Historicals: 0
* Historicals with Alien Influences: 1 (Mark of the Rani)
* Modern Day: 2 (Attack of the Cyberman. Sort of. And The Two Doctors).
* Other Stuff: the rest. Err... 8?
Sylvester McCoy stories:
* Historicals: 0
* Historicals with Alien Influences: 4 (Ghost Light, Remembrance of the Daleks, Delta and the Bannermen, The Curse of Fenric)
* Modern Day: 2 (Survival, Battlefield, Silver Nemesis)
* Other Stuff: 5
A couple of the historicals (daleks, delta) are almost modern day!
Cheers!