If someone commits a sexual assault against a child you'd probably expect them to be brought to justice. In fact, you'd usually assume they would go straight to jail. And you'd certainly find it very worrying if most offences against children went unpunished.

So you will be shocked to learn that fewer than one in 10 of more than 20,000 sexual assaults against children reported to police last year resulted in a conviction. These are serious crimes that include rape, incest and abuse of children through to prostitution and pornography.

We have only uncovered this situation by painstakingly contacting all 43 police forces in England and Wales with a Freedom of Information request. Our investigations have revealed that one in three of all sex crimes are committed against children.

Of the 23,097 victims the vast majority were girls (19,790) - six times the number of boys.

More than a fifth of these children hadn't reached secondary school age and almost 1,500 were five years-old or under. Perhaps most worryingly of all, we found that 426 children had been abused before but only one-third of the forces were able to supply this information.

For the last four years the NSPCC has collated these figures through a Freedom of Information request and during this period there has been no significant decrease in reported offences. And despite the number of convictions rising by around one-quarter, from 1,747 in 2007 to 2,135 in 2010, fewer than 10% of offences result in someone being sentenced.

Behind every number recorded by the police is a child who has suffered appalling abuse. A child who will need sustained support and care to rebuild their life. Yet tracking an individual child sexual offence victim through the criminal justice system is a complex process.

Today the NSPCC is calling for action to drastically reduce the number of sexual assaults on children. A concentrated effort has to be made if we are to start reducing this distressing level of offences, many of which are committed on extremely young and helpless children.

When you have a situation where more than 60 children are being sexually abused every single day, something is very wrong.

We also need a clearer picture of what is happening between an offence being reported and someone appearing in court. The police are doing their best to bring prosecutions but we need to understand why there is such a huge disparity between the two figures. The fact there are repeat offences against some children also shows not all are just one-off incidents and these children are being failed by the system time and again.

The NSPCC is doing what it can by using information like this from the police to tailor our treatment services - different approaches are needed depending on the age of the child. We are also pioneering new programmes, including our Schools Service which aims to work with 1.8 million seven-to eleven-year-olds over the next four years.

But we can't tackle this problem by ourselves. We need more members of the public to be aware of abuse and how to prevent it. And we want schools and parents to educate children about staying safe and reporting abuse.

It also requires a major effort from the government and the public to give children the protection they need and to provide more therapeutic programmes so the young victims of abuse can start to rebuild their lives.

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