The data collected with the DELPHI detector at centre-of-mass energies betw
een 130 and 172 GeV, during LEP operation in 1995 and 1996, have been used
to determine the hadronic and leptonic cross-sections and leptonic forward-
backward asymmetries. In addition, the cross-section ratios and forward-bac
kward asymmetries for flavour-tagged samples of light (uds), c and b quarks
have been measured. No significant deviations from the Standard Model expe
ctations are found. The results are interpreted by performing S-matrix fits
to these data and to the data collected previously at the energies near th
e Z(0) resonance peak (85-93 GeV).
The results are also interpreted in terms of physics beyond the Standard Mo
del: contact interactions, R-parity violating SUSY particle exchange and of
possible Z' bosons.