During the English renaissance, plays were primarily written for performance and play manuscripts were usually not sold to a printer before the play had had a successful run in the theatre. A number of plays have survived in manuscript form, e.g. John Bale's King Johan (rediscovered in the 1830s), Thomas Heywood's The Escapes of Jupiter, Philip Massinger's The Parliament of Love and Believe as You List, The Second Maiden's Tragedy (contested authorship), Richard Brome's The English Moor, Sir Thomas More (collaborative work, possibly containing Shakespeare's only surviving literary manuscript). Apparently, some researchers also include Thomas Heywood's The Captives and Walter Mountfort's The Launching of the Mary (see Manuscripts and their Makers in the English Renaissance).
Some of these are part of the British Library's MS Egerton 1994, but not all the manuscripts in this collection are considered autographs.
So how many English Renaissance plays (roughly from years the 1550 – 1625) have survived in manuscript form? (These manuscripts can be in the handwriting of the original authors or contemporary copies.) I am not asking for an exhaustive list of plays but a source that discusses the (number of) surviving manuscripts.