Photometry of symbiotic stars - an international campaign : IV. Z And, EG And, R Aqr, UV Aur, TX CVn, T CrB, BF Cyg, CH Cyg, CI Cyg, V 1016 Cyg, AG Dra, CQ Dra (4 Dra), YY Her, V 443 Her, SS Lep, AG Peg, AX Per, FG Sge, V 1017 Sgr, FG Ser (AS 296), PU Vul, AS 338, AS 360, MWC 560, GH Gem, He2-468