Values of the warp altitude above and below the Galactic plane at the Galactocentric radius R = 14 kpc for different tracers ordered by approximate age. The values have been taken from Table 1 in Romero-Gómez et al. (2019) or computed by us. The tracers used to investigate the warp cover neutral hydrogen H I (Levine et al. 2006b, L06), OB stars (Romero-Gómez et al. 2019, R19), pulsars (Yusifov 2004, Y04), Cepheids (Chen et al. 2019, C19), (Skowron et al. 2019b, S19), this study, RGB (Reylé et al. 2009, R09), (Romero-Gómez et al. 2019, R19), and red clump (RC) stars (Drimmel & Spergel 2001, D01), (López-Corredoira et al. 2002, LC02).