There is indeed data on mallard duckling survival, which in retrospect is not that surprising given the number of wildlife biologists and the interest of fish and game departments in the number of ducks.
One recent paper, Duckling survival of mallards in Southland, New Zealand, Erin J. Garrick et al, in The Journal of Wildlife Management, contains the following in the abstract:
In 2014, we investigated mallard duckling survival on different pastures relative to a suite of characteristics pertaining to the adult female, clutch, brood, weather, and habitat. We monitored 438 ducklings from 50 radio‐marked females to 30 days post‐hatch. Duckling survival was unaffected by pasture type but increased with duckling age, the presence of ephemeral water, and with greater distance from the nearest anthropogenic structure. Survival was lower for broods of second year (SY) females than for broods of after‐second year (ASY) females, in areas with more dense cover, and when ducklings moved, on average, greater daily distances. Cumulative 30‐day duckling survival ranged from 0.11 for ducklings of SY females without ephemeral water present to 0.46 for ducklings of ASY females with ephemeral water present.
Note that is only for the first 30 days.
In 'Survival of radio-marked mallard ducklings in south Dakota', Joshua D. Stafford and Aaron T. Pearse, Wilson Journal of Ornithology 119(4) 585-591 (2007), the abstract contains:
Survival of ducklings to 30 days was 0.42 at Oakwood (95% CI, 0.13-0.67) and 0.77 at Mickelson (95% CI, 0.42-0.92).
In 'Factors affecting survival of Mallard ducklings in southern Ontario', S.T. Hoekman et al., CONDOR 106(3) 485-495 (2004), they say:
Mean 30-day duckling survival across sites was 0.40 (range 0.07-0.50).
All in all, the odds don't look good for ducklings...