tasa tamaño mort. nac. mort. lech. pérdidas ovulación camada prenatal vivos neonatal dest. % <10 6.8 25.3 6.7 1.5 6.5 35 11-12 9.2 20.7 8.8 4.3 8.4 30 13-14 9.5 30.2 9.2 3.2 8.9 36.4 15-16 10.3 32.8 10.1 1.9 9.9 38 17-18 10.3 41.5 9.9 3.9 9.5 47.1 19-20 11 42.1 10.5 4.6 10.0 50