The seven-time world champion was put into a medically induced coma for six months after the incident in the French Alps.
Doctors operated to remove blood clots from his brain, but some were left because they were too deeply embedded.
Medics described his condition as 'extremely serious' after his admission to Grenoble Hospital, where he underwent two life-saving operations.
Three months later a statement was released confirming that the F1 champion was no longer in a coma and had left Grenoble Hospital.
Schumacher, who remains immobile and cannot speak, is understood to have a 15-strong team of medics looking after him at his home in Geneva, Switzerland.
In December 2016, a statement from his manager, Sabine Kehm, said: "Michael's health is not a public issue, and so we will continue to make no comment in that regard.
"We have to protect his intimate sphere. Legally seen and in the longer term, every statement related to his health would diminish the extent of his intimate sphere."
The statement continued: "Michael has always been very protective of his privacy, even during the most successful times of his career.
"He has always made sure there is a clear and distinct line between his public persona and his private one."
But his former teammate Johnny Herbert has revealed the F1 legend has 'good days and bad days'.
Friend Ross Brawn has said: "The family are conducting his convalescence in private and I need to respect that.
"So I don't want to comment on his condition beyond saying we're extremely hopeful we'll see Michael as we knew him at some point in the future."
Schumacher is believed to have been worth £500 million before the accident.
