NJLExus24

I am under the assumption that the 1992-96 ES300 has a stock horsepower of 188. Now, my car is a 1993, therefore being almost 9yrs old. My car runs great and has been treated with care of the past years, but approximately how much HP is lost over a 9yr time period? I do have a HPRacing exhaust and K&N Air Filter, but I know that I probably only gained maybe 5 hp from both together. Also, what are some good ways to gain lost horsepower without spending 100s of dollars??