;ADF;DF-GLS;PP;KPSS
c;–3.47**;–3.55*;–3.47**;0.29
e;–3.48**;–2.82*;–3.43**;0.35
y;–3.08**;–2.14**;–3.09**;0.28
tr;–4.22*;–3.07*;–14.31*;0.33
ed;–4.83*;–3.02*;–1.24;0.19
u;0.63;–0.07;0.62;0.68**