The values in the sppg10.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 center 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 combining in quadrature 
all the individual contributions in the column for sigma_ppg in Table 2.