It had the unintended result of drastically increasing the percentage of those leaving through West Berlin from 60% to well over 90% by the end of 1958. Those caught trying to leave East Berlin were subjected to heavy penalties, but with no physical barrier and subway train access still available to West Berlin, such measures were ineffective. The Berlin sector border was essentially a "loophole" through which Eastern Bloc citizens could still escape. The 3.5 million East Germans who had left by 1961 totalled approximately 20% of the entire East German population.