Its amazing.....the people on this site are among the most intellectually arrogant, yet share the least amount of knowledge.
To the original poster. ...
While its impossible to predict what you SHOULD run, based off of the typical progression most athletes have, a 52sec runner generally ends up in the 49-50 range the following year if they possess the necessary tools. Just being a year older isnt going to guarantee anything, but a more sound race strategy, smarter more efficient training and good health will likely put you in the 50.xx range. So you would have to give a little more info to give the crowd a chance to answer your question competently.