Update needed The results of the EMC collaboration ration 1 in the low x region 1 in the high x region are no longer latest state of the art In the past 30 years many more experiments have been done with considerably higher precision The ration per x has turned out to be a wavy curve rather than a linar relation at low x 0 1 it is less than 1 in intermediate x approx 0 2 there is a slight overshooting and then it gets negative again At very high x close to 1 it gets positive again See e g Fig 2 in