It is hard to say how tall he will be in the future.
CZW males grow up for long time. Of course, first 9-10 moths they grow up very quick, after that age they rise much slower.
Some lines are long-growing, at the age of 3 years we can say that they are finnaly 100% overgrown. Some other lines have they finnaly size when they are much younger (18-24 months).
If Your CZW has 67 cm now it is possible that he will be 70 cm in the future. Be patient
