DB4's had a total of 264 1999's made. As per this web site.
http://www.bimota-freunde.de/
If you want to look click on the left side link called
Schrauber-Archiv, then on the red link called "...Typenliste Bimota von 1975 bis 2000 ...". The only heading anyone may not figure out is "Anzahl" which means quantity.
There is this one also
http://www.bimota-enthusiasts.com/ that shows alot of info. but not on DB4's.
I think Europe is the place for info about Bimota, because there are so many there.