Replacement fertility is generally slightly higher than 2 (the level which replaces the two parents) both because boys are born more often than girls (about 1.05–1.1 to 1) and to compensate for deaths prior to full reproduction.
替代生育率一般略高于2(替代双亲的水平) ，这既是因为男孩出生的次数多于女孩(约1.05-1.1-1) ，也是为了补偿在完全生育之前的死亡。