What does "estimated rate" means in survival trees in R?

Hello I am plotting a survival tree in R

fit <- rpart(Surv(week, arrest) ~ fin + age)
summary(fit)

My tree works but when I get the output I don't understand what means the estimated rate ? Is it the estimated hazard rate ratio ?

Node number 1: 432 observations,    complexity param=0.03809064
  events=114,  estimated rate=1 , mean deviance=1.165441 
  left son=2 (366 obs) right son=3 (66 obs)
  Primary splits:
      age   < 19.5 to the right, improve=19.216100, (0 missing)

Node number 2: 366 observations,    complexity param=0.01767241
  events=81,  estimated rate=0.820937 , mean deviance=1.074816 
  left son=4 (224 obs) right son=5 (142 obs)
  Primary splits:
      age   < 23.5 to the right, improve=5.093023, (0 missing)
      fin   < 0.5  to the right, improve=4.795953, (0 missing)

Thanks for your help, Lucie.