Percentages are the nightmare of many a school pupil, and the ones in the latest political poll represent a nightmare for the Labour Party.
For anyone not a dab hand at the maths, a four point fall to 15pc in Labour's rating since the election may not look too bad. But it represents a percentage fall of more than 20pc -- which means almost one in four of those who voted Labour last year have now deserted the party.
Just like school, one cannot do well unless one learns one's lessons. This the Labour Party seems signally unable to do. It has bitter experience of how the junior partner in a coalition tends to suffer more from voter dissatisfaction. This was bound to be even more the case in this government, faced with the most unpleasant task of any administration since the Civil War.
Labour should have known that, and been ready to apply the inevitable financial corrections in a way which would do it least damage and, even more, to have policies in other areas which it could distinctively claim as its own.
Instead, we got the idiocy of, "Labour's way or Frankfurt's way". In a desperate attempt to get votes, the party left people with the impression that the pain would be less with Labour in charge.
Now, many of those who did vote Labour are showing their disappointment. Eamon Gilmore and Labour could do little about the economic and fiscal situation, but they should have led the way on reform of government structures, accountability for failure, and the curbing of vested interests, whether in business, the professions or the trade unions.
They did very little on any of these. There is little sense that the general election changed anything in Irish politics and governance, even if the present cabinet is more energetic and engaged than in the latter days of Fianna Fail.
Not surprisingly, the poll shows that Fianna Fail is not yet a credible alternative. Much will depend on whether it can become one before the next election. If it does, Fine Gael's solid ratings may also begin to slip. If it does not, the advantage will lie with Sinn Fein.
Sinn Fein has the luxury of presenting policies even more implausible than those of Fine Gael and Labour before the election, without the fear of having to try to put them into practice any time soon, but that presents its own dilemmas.
The voters may reject Sinn Fein's more impractical, and dangerous, policies once a general election looms near. It is very easy to lodge a protest with a pollster as compared with choosing a government.
Even if they don't, Sinn Fein itself should be careful. If it stands on an impossible platform, in the hope of garnering votes, it will suffer the same fate when its empty promises have to be broken. There is even less sense in "Sinn Fein's way" than there was in Labour's.
Stark insight into hospital failures
The continuing need for openness and accountability could not be more starkly illustrated than in the report on the Tallaght Hospital A&E department from the Health Information and Quality Authority.
The main reason for welcoming it is that we can learn a lot from it. In particular, given the times we live in, it shows that lack of money was not the only cause of the failures in Tallaght, and perhaps not even the main one.
There is good reason to think that this is the case in much of the health service, although one must hope situations such as that outlined in the report are rare. But Tallaght may have differed more in the scale of its failings rather than their nature.
The sorry state of affairs, reported by the authority, led to appalling conditions for patients in the emergency department.
But there may be wider problems in what the report calls a "cultural belief" that the routine practice of accommodating patients on trolleys in corridors is acceptable.
The inescapable fact is that the €14bn health budget will continue to fall for some years yet, and will see no significant real increase for the foreseeable future. It will need first-class management, sensible structures and determined removal of anyone who is not up to the task, to maintain, still less improve, services.
The report shows just how far we have to go.