The 7 month deployment + 15 month sustainment (19% availability) is apparently a matter of money, so in time of war you could theoretically have a 22 month period of availability for each carrier (61% availability). Other articles suggest deployments can actually last up to 9-10 months due to need, I suppose because there are currently only 10 carriers vs the usual 11.
If the PLAN follows a similar deployment strategy, you would expect 1 carrier deployed at all times with 3 to 4 carriers behind it out of action.