How many people were raised from the dead by Christ during His ministry?
The widow of Nain’s son (Luke 7:11–17), Jairus’ daughter (Luke 8:52–56), Lazarus of Bethany (John 11) and of course, Christ (by the Father or Christ’s deity who is omnipresent and omnipotent). See Rom’s 6:4, Acts 2:32 and John 10:18
The passage below from the Gospel of Matthew shows ‘many’ coming from the grave at Christ’s resurrection. So, there were the four mentioned and then, ‘many’. 

51 And, behold, the veil of the temple was rent in twain from the top to the bottom; and the earth did quake, and the rocks rent; 52 And the graves were opened; and many bodies of the saints which slept arose, 53 And came out of the graves after his resurrection, and went into the holy city, and appeared unto many. 54 Now when the centurion, and they that were with him, watching Jesus, saw the earthquake, and those things that were done, they feared greatly, saying, Truly this was the Son of God.

The Holy Bible: King James Version, Electronic Edition of the 1900 Authorized Version. (Bellingham, WA: Logos Research Systems, Inc., 2009), Mt 27:51–54.