Terry, your anomalies are easily resolved.
Of course the (geometric, i.e. percentage) rate of growth was not steady.
Girls were prettier in those days.
Closer to original perfection*, right, as the Adamic descent had barely started?
As a result other things happened a lot more often.
And about 9 months later other things happened a lot more often too.
So, you see, the Bible wins again!
Bzzzzt, sorry - but thanks for trying.
Ooops, just seen my blunder.
In "Life Everlasting in Freedom of the Sons of God", a great Watchtower publication from 1966, we learn that God brought animals to Adam in order to have sex with. Here, from pages 45-7:
21 Before the man (adám) ever asked for a human companion, God his Creator knew what was good for him. Of course, the man’s having a human companion could influence him for good or for bad, for obedience toward God or for disobedience toward God, for everlasting life or for everlasting death. But the “God of faithfulness” would provide a companion for Adam for good, toward his obedience, toward everlasting life. The Creation account makes all that plain, for, in Genesis 2:18, it reads: “And Jehovah God went on to say: ‘It is not good for the man [adám] to continue by himself. I am going to make a helper for him, as a complement of him.’”
22 Before God created anything new, a woman, God left the man free to determine whether there was a suitable companion for him among all the lower animals. He did not oblige the man to go seeking a companion among them, thus requiring the use of much time on the man’s part, but Jehovah God brought the various beasts of the earth and the flying creatures of the heavens before the man. God gave the man the freedom to name these creatures. But the perfect man, created in God’s image and according to God’s likeness, was not inclined to bestiality. He merely acquainted himself, unafraid, with them and named them, but he found among them no suitable companion for himself. As a lone human on earth he continued to worship his God and Creator, not lower animals. He needed no command from God against animal worship. He had just the one law against improper eating.—Genesis 2:19, 20.
23 After the man fully exercised his freedom to reject any of the lower creatures as a companion and helper for him, God acted. "Hence Jehovah God had a deep sleep fall upon the man and, while he was sleeping, he took one of his ribs and then closed up the flesh over it place. And Jehovah’s God proceeded to build the rib that he had taken from the man into a woman and to bring her to the man. Then the man said: ‘This is at last bone of my bones and flesh of my flesh. This one will be called Woman [Ishsháh], because from man [ish] this one was taken.’"—Genesis 2:21-23.
24 This reveals that God told the man just how the woman had been created, to show to the man that she was related to him in flesh and bone, for she was a part of him. Adam’s words on accepting the woman as his wife make plain that he exercised his free choice to have this woman as his helper and companion. She was the last one of the creatures that God brought to Adam to see which creature he would choose as his life-long companion. Then to show that they would have children who, in turn, would marry, God went on to say: “That is why a man [ish] will leave his father and his mother and he must stick to his wife and they must become one flesh.”—Genesis 2:24; Matthew 19:4,5.
25 It was after the man accepted his perfect wife at God’s hands that God blessed them and told them to be fruitful (...)
While it isn't clear if Adam-of-the-Watchtower tried it out for a quickie, the WTS do make it clear that none attracted him enough to be a mate.
So God varied it a bit
And, judging by her appeal, I'd have thought it needed quite a few hundred generations before the birth-rate picked up.
So, you were right all along, Terry.
There's an(other) anomaly there.
("Quick to concede error" Class)