Relationship between the Compton dominance and ﹩{\nu }_{\mathrm{sy}}^{\mathrm{pk}}﹩. The color scheme for data symbols follows from Figure 5. All of the upper limits, including the ones from this work are represented by green filled triangles. The black horizontal lines represent the range of ﹩{\nu }_{\mathrm{sy}}^{\mathrm{pk}}﹩ for redshifts from zero to the upper limits, provided in our sample.