Season Four Summary

Thanks to the writers' strike there were only 16 episodes this season, half of which were dedicated to House's Survivor game. The second half of the season featured House's final motley team of three new Housepets, Hadley (Thirteen) the internist, the Kutner the rehabilitative and sports medicine specialist, and Taub the plastic surgeon. Foreman the neurologist rejoined the team as well and Chase and Cameron remained on the sidelines in Surgery and Emergency Medicine respectively, contributing only rarely.
House was away treating his own patient in Whatever It Takes, and Foreman diagnosed a patient in another hospital in 97 Seconds. These two cases were not covered here, and except for them there was one patient per episode.

Patients treated: 16
Lives saved: 14
The patient in Wilson's Heart died because her body was too damaged to survive, and the patient in 97 Seconds died because competition between the fellowship contestants interfered with his care.

House: 16 diagnoses + 33 credits - 1 error = 48 total
Kutner: 4 diagnoses + 10 credites - 1 error = 13 total
Thirteen: 2 diagnoses + 11 credits - 1 error = 12 total
Foreman: 1 diagnosis + 11 credits - 1 error = 11 total
Taub: 3 diagnoses + 6 credits = 9 total
Chase: 2 diagnoses + 3 credits = 5 total
Cameron: 2 credits - 1 error = 1 total

My conclusions: After four seasons, 96 patients have been treated by House and his pets and 82 lives were saved by them.
The new team started off better than the originals did, because they had to. After the first season they're all pretty equal to each other. Taub has less overall points, but he also gets less focus than the other characters.