You may think Ronaldo scored more goals in this season because he is now more experienced in the Saudi league and he knows the league better than before but the fact about Ronaldo is he is also getting older and he shouldn't have better performance normally because of his age.
However, he doesn't show that the age is an obstacle for him to compete in SPL. He is in the top of SPL top scorer, it means he still plays better than any other strikers in Saudi league. No doubt he is getting old, he will be 39 years old this year. But I see that he still has a big ambition and intention to win any title in Saudi. He is also very obsessed to be the top scorer in SPL.
Ronaldo has good support from his team mates and he receives many key passes as well as chances to take penalty shots for Al Nassr. If he won't get injuries, he will be able to score more goals for Al Nassr and can aim at his 1000th goal.
I don't think he will get a serious injury. Ronaldo is one of the players who is very rare to get injury. It is because Ronaldo keeps his health very well. He doesn't drink alcohol and keeps to a healthy diet. He also has a healthy lifestyle. So, I am sure he will be healthy during this season. I assume he will claim the 1000th goal soon.