In the UCL:
16/17: 2 goals and 1 assist
15/16: 0 goals and 1 assist (winners medal)
14/15: 2 goals and 1 assist
13/14: 6 goals and 4 assists (winners medal and winning goal)
Seriously he hasn't been significant in their UCL runs, hes had very little impact for an attacking player, especially the last 3 seasons.
Apart from the 13/14 season.
In La Liga he has more than a goal every 2 games (54 in 100), which is pretty good considering he plays second fiddle to Ronaldo (i.e. doesn't get to take the majority of free kicks/penalties). He's also been really unlucky with his injuries. Last season he was almost scoring a goal a game (19 in 23 in the league), again injuries didn't help him.
In the Champions League he's pivotal in the big games. Yes, he should be scoring more goals but I'll give you three instances of his importance to Real Madrid UCL:
2013/14
- Scores the winning goal in the final
2015-16
- Scores (own goal, but he still made it) the only goal in the semi final victory over Manchester City.
- Also, earned the free kick from which he assisted (with a header) Ramos' goal in the final.
His big game importance has been also seen in the Copa del Rey where he scored the winning goal again in the 2013/14 final.
I just hope he gets less injuries, as he really is a brilliant player when fit.