There is probably no way to know for certain, due to many circumstances, however, here is an interesting report from the University of Southern California:

http://www.uschina.usc.edu/w_usci/showarticle.aspx?articleID=13037&AspxAutoDetectCookieSupport=1

It's not common but shit do happen occasionally

  Well it's a patriarchal society, so women don't receive equal respect to men. To me that gives an ignorant man license to hurt a woman, in his feeble mind anyway. Personally I think China and the Chinese are a disgrace to the word decency with regards to the subject of rape. I can think of no other way to put it. That there are not even charges for a man to file if he were to suffer such an act, as I have just read in Giadrosich's article above, is abominable. Does that also count for male children? And the fact that women are afraid to come forward and ask for help, let alone justice, for fear that they will be looked down upon by their community and even their family as something dirty, makes me want to vomit upon this country. To any Chinese readers of this I am sorry for such harsh words, but I mean every one of them. That a child can suffer such torment only to receive a lifetime of judgement and be looked down upon and forced to suffer in dreadful silence, rather than be held up with love and respect as someone who is a survivor of such a vile and pernicious act as rape, is disgusting to me. It is an absolute sin and, at the end of the day, just another example of how the collective nation of man is still truly and utterly, in its infancy.

It's maybe (but not likely) less common than other countries, but newspapers rarely report any of this type of crime unless it involves children, so it may seem like it is rare but truly isn't.  The government and news organizations like to pretend if they don't report the problem, people will believe there is nothing to be worried about.  Also, it is likely many rapes go unreported to the authorities, likely because of trust of the police, and possible situation of having family find out what happened.  Most Chinese families still won't have the sex talk with their son or daughter, and sex is not a topic allowed in schools, so many girls probably don't quite understand the significance of being raped... until it haunts them dearly for the rest of their life as they stay silent.

YES. 

My friend was at the hospital once when a rape victim came in in Beijing. She later spoke to the doctor when she saw him outside on his break. He told her rape victims come in so often they don't even bother calling the police. 

Yes, but unreported

https://www.yahoo.com/news/6-years-gone-myanmar-woman-042453020.html

How many sad stories like this occur in China? We will never know.

https://www.thestar.com/news/world/europe/2019/03/13/italy-outraged-as-court-finds-victim-too-ugly-to-be-raped.html

Damn Italians say no one would rape an ugly girl, somebody must think they have the most beautiful women in the world.

https://metro.co.uk/2019/06/05/new-law-will-force-child-sex-abusers-pay-castration-released-jail-9824047/

So Alabama says you rape someone under 13, before your time is served to go home, you have to pay for chemical castration. It could be worse, in the philippines if the girl has not had a period yet, you get the death penalty. I wonder if the law is gender neutral and what happens if you transition to avoid the penalty, the things you have to consider in the modern age.

I was riding home on my scooter one night. This happened a couple of years ago. The raod was next to the river. All of a sudden a girl jumped our into the road and so I slowed down and stopped. She was half nacked. She only had a shirt on and was bleeding between her legs. I took my shirt off and tried to cover her up. I put her on the back of my scooter and took her to the only police station that I knew at the time. My wife, her mother and the ladies boyfriend eventually arrived at he police station. The next day the boyfriend phoned to find out if she had been raped. My wife told me that he wanted to know if she had been raped because if she had been raped then he would leave the girl as Chinese guys only marry virgins. The police phoned a couple of weeks later and told us that they had arrested the rapist next to the river. They would attack girls that were walking next to the river, take all their belongings and rape them. This was about eight years ago. Things have changed since then. There are a lot more cameras in the streets and so on.