Hello Claudia:
If you use Origin or Excel or milimetric paper with this data you'll get a similar "L" or "V" invert curve...
Your you must draw up a pair of tangent lines to the curve, these lines will be crossed and in this point you will get the equivalence point. You will obtain the variation of temperature.
It is important to indicate that in most of the titrations, normally the obtained curves are not straight. Why? This is a one way to get the equivalence point (graphical way).
Do you know what is the Concentration of HCl and Acetic Acid?
Regards,
Chiralic