How should the pressure coefficient distribution from a wind tunnel experiment be interpreted?
First, your pressure values cannot be the measured pressure, because they are negative. This indicates that they are pressure differences.

Next, their magnitude is too low to be in Kilopascal. Could it be that you list already the pressure coefficient?

Third, when plotting the pressure coefficient, it is customary to invert the Y axis, so the most negative value is on top. This just makes the plot look more familiar.

If I do this with the tabulated values, this is what I get:



Plot of tabulated values (own work). I extended the Y axis down to +1 on purpose, because this is the stagnation pressure coefficient in in compressible flow. Your data looks like that of a very thin symmetrical airfoil at an angle of attack near 0°.

Now look at this computed plot of pressure coefficients of symmetrical airfoils at zero angle of attack (source):



Inviscid pressure distribution of symmetrical NACA airfoils. The black line looks like your data. Unfortunately you never mentioned which airfoil the measurement is from, but to me it looks awfully like a NACA&nbsp;0006 (or even something thinner).