text: Average Time Served 
  Average Time Served 
  
  For the determinate population, the monthly inflows to prison are based on the 
  custodial convictions projections described above. These custodial convictions 
  include offenders that may already be serving a sentence for a previous crime 
  or those who would serve their whole custodial sentence on remand, meaning 
  that they would not be a new reception to prison. To convert from custodial 
  convictions to prison receptions we apply a conversion ratio derived from the 
  historical proportions of custodial convictions to prison receptions for each 
  sub-population averaged over the last twelve months of historical data (April 
  2013 to March 2014 inclusive). 
  
  Monthly outflows for the determinate population are based on observed 
  custodial sentence lengths and the observed percentage of sentence length 
  served taken from October 2013 to April 2014. Each projected offender that 
  enters the model is given a custodial sentence length that is randomly 
  selected from the relevant distribution. These distributions are populated with 
  custodial sentence lengths from actual offender receptions who share the 
  same characteristics of offence, gender and age group in the observed time 
  period. The percent of custodial sentence length served is derived in the same 
  manner, except that the observed distribution is made up of discharged 
  offenders further disaggregated by custodial sentence length band. 