What counts as "proficient" for the language section of the Common App?

I’m debating whether or not I should put on my Common App that I’m proficient in Spanish. I don’t speak very well, but it gives the option to say you’re just proficient in reading and writing. I’m in my fourth year of Spanish and I’ve been studying it on my own time outside of class since I started taking classes. I also got a 660 on the Spanish Subject Test Without Listening (which, from what I can tell, is about average). Would it make sense to say I’m a proficient reader and writer, or should I just not put anything down at all?

Here’s my definition: if you would be willing to write your application essays and/or have your interview in the foreign language, you are proficient. There are no extra credit point award, so if you’re not proficient, don;t claim it.