A person involved in a murder is brought to you for determination of age since the defence attorney wants him to be treated as a minor. The results of Xrays are as given below: 1) All the epiphyses of the elbow have fused 2) All the epiphyses of the shoulder joint have fused 3) The epiphyses of the inner end of the clavicles has fused 4) The ramus of pubis and ischium has fused What is the approximate age of this person assuming that it is a male?