The values in the sppg08.dat-file correspond to:

M^2_{\pi\pi}  dsig_ppg/dM^2_pp  sigma_stat sigma_syst

The M^2_{\pi\pi} value stands for the middle of the bin (the binwidth is
0.01 GeV^2). sigma_stat stands for the square root of the diagonal element in the
covariance matrix of the statistical error. sigma_syst is the systematical
uncertainty in each bin as derived from adding in quadrature the entries in 
the leftmost column in Table 5 in arXiv:hep-ex/0809.3950.