The CP-violation parameter \etazero is determined through the eigentime-dependent asymmetry in the rates of initially tagged \kzerob and \kzero decaying to \pizero \pizero. From the analysis of the complete data set we obtain the values $ \absetazero = [2.47 \pm 0.31_{\mbox{stat.}} \pm 0.24_{\mbox{syst.}}] \times 10^{-3} $ and $ \phizero = 42.0^0 \pm 5.6_{\mbox{stat.}}^0 \pm 1.9_{\mbox{syst.}}^0 % \pm 0.3_{\mbox{$\Delta$m}}^0 . $
