Integrated flux of radio continuum at 6 cm versus integrated flux of mm-RRLs at 3 mm. The black solid line indicates the best-fit line determined by a xy-bisector fit to the data. The black dot-dashed and dotted lines indicate 3σ integrated fluxes for IRAM 30 m (2.22 Jy km s^-1) and Mopra 22 m (8.54 Jy km s^-1). The color bar represents an angular diameter of continuum source in units of arc second. The black filled-circles show no angular size for unresolved radio sources. The errors on the integrated fluxes of mm-RRLs are 1.82 Jy km s^-1 on average.