Israel's government number-crunchers may be good at predicting inflation, petrol prices and the cost of cottage cheese. But it seems they just cannot get a grip on how much Israeli Jews love children - and therefore how many babies they are having.

Shifting fertility levels among Jews and Arabs are not just a challenge to the nation's schools, which are going to be bulging at their seams but, some would say, also call into question what people know about the conflict.

When, in 2000, the state's Central Bureau of Statistics projected how many babies Jewish women would be having a quarter of a century later, the experts thought the number would either drop to around 2.1 children per couple or stay steady at around 2.6. But the trend has been towards more babies, not fewer.

The most current CBS figures show a steady upwards trend in the Jewish fertility rate and, in the latest year surveyed, 2014, it reached 3.1.

Today - in 2016 - demographers estimate that Israeli Jews have more children, on average, than Egyptians, Iranians or Lebanese.

Interestingly, these figures are not just a reflection of the fact that the Orthodox population, who tend to want more babies than others, has grown. Secular Jews are also having more children.

In the world of Israeli politics, population numbers are important. The peace camp has long been saying that Israel needs to make peace with the Palestinians and wash its hands of much of the land captured in 1967 before the "demographic time-bomb" explodes. As the assumption has been that Arabs have far more babies than Jews, at some point down the line, it is argued, a prime minister in Jerusalem will cast an eye over Israel and the West Bank and realise that he or she is in control of more Arabs than Jews. Israel, it is said, would then encounter the nightmare of being a minority ruling over a majority.

As Jewish fertility has risen, the rate among Muslims has fallen from 4.7 in 2000 to 3.4 in 2014. According to official statistics, Palestinian fertility rates have taken a dive since the late 1990s: from 5.5 to 3.7 in the West Bank in 2014 and from 6.9 to 4.5 in Gaza.

The figures reduce the power of the peace camp's argument about the urgency of a two-state solution, and explain why its advocates have focused on security issues when advancing their case in recent months.

To the pro-settler right, the figures are cause for glee - more fuel for the argument that Israel's continued presence in the West Bank is sustainable.