"Muscovy will lay up to 180 eggs a year and hatch about four sets of ducklings if they get lots of high protein feed. Muscovy ducks are great mothers and do a good job raising their young. Muscovy take longer to hatch than other poultry... an egg takes 33 to 35 days to hatch. A chicken, for example, hatches in 21 days."
This is a quote from this site....    
http://www.moosemanorfarms.com/about-muscovy-ducks.html
another site was higher on the eggs per yr...
I have nest boxes for my ducks and they will lay their eggs in the boxes 90% of the time, I find  1 or 2 a week on the straw floor (outside the boxes) probably cuz they were ready to lay and another duck was in one of the boxes, maybe??  I collect my duck and chicken eggs every day and they continue to lay their eggs every day; sometimes they will move to a different box and then go back to the same box.  They lay this way only when they are NOT broody. my ducks lay their eggs early; between 6-8am, once in awhile i will find one out in the yard or pool.
When they are broody a few ducks will lay their eggs in the same nest box every day and start building up the nest as i give them clean straw ea day. their nest will get huge. only 1 duck will sit on this nest of eggs (if i let them). if other ducks are broody they will collect eggs and make a nest also. Its a communication between the ducks that they are supposed to lay their eggs in the broody ducks nest (if the broody duck wants their eggs) its amazing how they pic and choose the eggs they want.
But scovy's are different, they will lay their eggs in a nest up high, if you provide this for them, i think....  @Miss Lydia  can help you out with this information, if you need her help?
Hope this helps anyone.