When I applied last year I was offered 50%, which seems to be their standard package, with a few outstanding apps getting full funding. I know a few others who were offered half-tuition, and know that full funding is more rare and haven't heard of anyone getting an offer less than 50% or anything other than half or full tuition. They may be out there, but that's the impression that I get. The ones getting full funding seem to fit the profile you might expect: really good numbers, a lot of language coursework, etc.
I'm not sure what tuition will be like next year, but it may be worth keeping in mind that while I thought 50% wouldn't be viable with their notoriously high tuition rates, my acceptance letter also bore the surprising news that tuition across the board would be reduced from around $50k to around $30k (as I recall). So while the $15k a year a standard funding package would entail is slightly more than what you might pay at other comparable institutions, it's a lot less than the untenable rates their AM program had developed a reputation for, and the degree may be well worth it if your interests dovetail with strengths in the program (which are many). The option to petition in-house for PhD admission has to be worth something as well. Also, cost of living may be appreciably more reasonable than some alternatives, especially if you are looking at programs in Boston or NYC. I remember being surprised at the relatively low rent in the area. Just something to consider. Best of luck with the application season!