# Figure 16

 Ratios ($K^+$ + $K^-$) / ($\pi^+$ + $\pi^-$) and K$^0/\pi$ as a function of $\sqrt{s}$. Data (full symbols) are from pp collisions, (at $\sqrt{s}$ = 17.9 GeV by NA49 [34,35], at $\sqrt{s}$ = 200 GeV by STAR [32] and at $\sqrt{s}$ = 900 ALICE, present work) and(open symbols) from $\rm\overline{p}$p interaction (at $\sqrt{s}$ = 560 GeV by UA5 [37] and at the TEVATRON by E735 [36,38]).