FEW Lebanese politicians have weathered their country’s rolling political storms better than Michel Aoun. The 81-year-old rose from warlord to military commander to prime minister at the end of the country’s lengthy civil war, before Syrian warplanes bombed him into exile in 1990. Having made peace with his former enemies, he returned years later to lead the most powerful Christian party in Lebanon. On October 31st he became the country’s 13th president.

It has taken Lebanon more than two years and 45 failed attempts to elect a president. The political deadlock has paralysed decision-making and crippled basic services in a country already buckling under the strain of 1m Syrian refugees. It has also exposed the clunky inadequacies of Lebanon’s political system.

When it was first carved out of the crumbling Ottoman empire, Lebanon was intended as a haven for Christians in the Middle East. Their numbers have since dwindled after decades of war, emigration and low birth rates. But their political clout remains. Before the civil war of 1975-1990, Lebanon’s Christians enjoyed six reserved parliamentary seats to every five given to Muslims. The allocation was made on the basis of a census in 1932. Academic studies suggest that, at the time, Christians made up just half the resident population but their numbers were inflated by questionably counting emigrants (most of whom were Christians).

Under the Taif accords that ended the war the ratio of seats was adjusted to parity–the defeated Christians were given five seats for every five for Muslims. It was clear that Christians were still being over-represented, but it was hard to say so definitively as there had been no census since 1932.

Official government figures obtained by The Economist show just how lopsided this arrangement has now become. The data, taken from the voter registry, reveal that only 37% of Lebanese voters are Christian. It is little wonder that many fear a new census may inflame tensions in a country deeply divided along sectarian lines.

“A new census would upset the order of things,” says Walid Jumblatt, the leader of Lebanon’s Druze (a small esoteric sect which developed out of Islam but has little in common with it) and chairman of the Progressive Socialist Party. “It is a very sensitive issue. The results of a new census would cause many problems. It would irritate some sections of the community. There are already too many tensions between Shias, Sunnis and Christians. A census is not something we need right now.”

The Economist obtained the voter registration lists, which include information on the religious affiliation of the country’s 3.6m eligible voters, after they were posted on a website belonging to the Interior Ministry. They have since been taken down.

The data show that Maronite Catholics, once the largest sect in Lebanon, now make up only 21% of voters. That crown has passed to the Shias, now 29% of those listed, followed closely by the Sunnis, who make up 28%. Given their lower birth rates and higher rates of emigration, Christians are likely to be an even smaller share of the general population than they are of voters. Yet while the Sunnis and Shias each have 27 seats in the 128-member legislature, the Maronites have 34 (see chart 1).

Whenever Lebanon erupts in violence, efforts are made to tinker with, though not fundamentally alter, these imbalances. The Taif Agreement stripped the Maronite presidency of much of its original power and strengthened the roles of both prime minister and Speaker of parliament, which are always held by a Sunni and Shia, respectively. Another agreement in Doha after violence flared up in Beirut in 2008 saw the Shia-led opposition under Hizbullah win the right to veto major decisions. Parliament’s dysfunction, seen in its inability to elect a president for more than two years, is partly a product of these power-sharing agreements. Dally as the parliamentarians may, the fib underpinning Lebanon’s political system will only become more egregious. Records of voter age also included in the registry show how Muslims make up a large majority of the country’s young (chart 2). So Christians will find their control over half of parliament even harder to justify in the years to come. Try as he may, Mr Aoun will face an uphill battle if he attempts to claw back the presidential powers lost by Christians at Taif.