Cristiano Ronaldo is currently leading Serie A's goalscoring table hitting the back of the net 15 times since the start of the competition, followed by Inter Milan's Romelu Lukaku, Lazio's Ciro Immobile and AC Milan's Zlatan Ibrahimovic with 12 goals each.
To be fair, that doesn't tell the whole story, as these performers don't share the same amount of games/minutes, which may have prevented some of them to get a much better ranking.
For example, Zlatan Ibrahimovic wasn't able to feature in any single game with the Rossoneri during a period of 2 months due to an injury, which have costed him the fall from the first place.
So let's take a look on a bigger picture, which is the ranking by average goals per minute (only players with 10 goals at least):
1. Luis Muriel - 1 goal every 48 minutes (10 goals)
2. Zlatan Ibrahimovic - 1 goal every 52 minutes (12)
3. Cristiano Ronaldo - 1 goal every 79 minutes (15)
4. Romelu Lukaku - 1 goal every 103 minutes (12)
5. Ciro Immobile - 1 goal every 106 minutes (12)