Line fluxes vs. source properties: stellar mass, stellar X-ray luminosity, mass accretion rate, 0.9 mm continuum flux, ¹³CO flux, HCO⁺ flux, and H¹³CO⁺ flux. All fluxes are scaled to a common distance of 160 pc. Marker shapes indicate different source types: filled circles are continuous T Tauris, open circles are transition disks, and stars are Herbigs. Continuum flux values at 0.9 mm were measured from our Band 7 observations and are reported in Table A2. ¹³CO J = 2−1 flux values were retrieved from K. I. Öberg et al. (2021) for AS 209, GM Aur, HD 163296, and MWC 480, F. Long et al. (2022) for DM Tau and V4046 Sgr, and M. Leemker et al. (2022) for LkCa 15. The black line shows the median fit from linmix and the gray lines show samples from the posterior distribution.