This isn't an answer to your question, but nevertheless, the percentage matters less than the overall trajectory of the economy, towards further socialization (ie centralization and interconnection, development, etc) or not, and whether it still is dominated by a proletarian state that controls at minimum the commanding heights of the economy. At a certain level of development, private property begins to fall apart and only central planning presents a path forward, ergo development is the number one priority as long as the state constantly sides with the interests of the proletariat. This will naturally lead to a collectivized economy as it develops.