Timing residuals of PSRs J0030+0030, J0613-0200, J0751 + 1807, J0900−3144, J1012+5307. For each pulsar, the residuals before and after subtraction of DM and monochromatic red noise are shown. The squares, circles and triangles represent P-band, L-band and S/C-band observations, respectively (see Table 2 for frequency coverage of each band). The blue/filled and black/unfilled symbols indicate the new backend data and those from EPTA DR1, respectively.