Near as I can tell it's about 1%. But don't forget these are only first marriages of people 15 to 44. I would expect older people to have a higher death rate and second plus marriage to have a higher divorce rate as well. Here's the whole paragraph.
"Looking at 20 years, the probability that the first marriages of women and men will survive was 52% for women and 56% for men in 2006–2010. These levels are virtually identical to estimates based on vital statistics from the early 1970s (24). For women, there was no significant change in the probability of a first marriage lasting 20 years between the 1995 NSFG (50%) and the 2006– 2010 NSFG (52%) (Table 5). The remainder of first marriages that ended within a 20-year period were dissolved by divorce, separation, or rarely, by death. "
"Looking at 20 years, the probability that the first marriages of women and men will survive was 52% for women and 56% for men in 2006–2010. These levels are virtually identical to estimates based on vital statistics from the early 1970s (24). For women, there was no significant change in the probability of a first marriage lasting 20 years between the 1995 NSFG (50%) and the 2006– 2010 NSFG (52%) (Table 5). The remainder of first marriages that ended within a 20-year period were dissolved by divorce, separation, or rarely, by death. "