Mozart Requiem... How Much of the Requiem did Mozart Complete?

This question of how much of the Requiem Mozart actually wrote is a bit complicated since there are several composers, including Franx Xaver Sussmayr, a pupil of Mozart's, whose handwriting bore a striking resemblance to Mozart, who had a part in completing the work.   Mozart's creative process, from the autograph  manuscripts left behind of the Requiem reveal that Mozart began by writing the choral parts and figured bass line, with some indications to scoring.  Later, he would fill in the other orchestra parts. 

Mozart appears to have completed in full score the opening "Requiem aeternam" and the "Kyrie" while sketching in choral parts with figured bass the "Dies irae," "Tuba mirum," "Rex tremendae," "Recordare," "Confutatis," "Domine Jesu," and "Hostias."  The last music Mozart is known to have written is the eighth bar of the "Lacrimosa," translated as "Mournful Day."  Sad that would be the title of his last music written, as so much of his music uplifted, bringing sunshine, hope, and happiness to every day...