  We evaluate the ratio of baryon and electric-charge cumulants at second order
from the recent experimental results at $\sqrt{s_{_{NN}}}=200$ GeV by the STAR
Collaboration. The baryon number cumulant is reconstructed from the proton
number distribution, and effects of the finite acceptance on the transverse
momentum are corrected assuming the independent particle emission. We show that
the obtained ratio has a dependence on the rapidity window. Comparison of the
result with the hadron resonance gas model and lattice QCD numerical
simulations suggests that if the fluctuations are generated from a thermal
medium its temperature is significantly lower than the chemical freezeout
temperature.
