Add pension contribution splits

[nikhilwoodruff]

We should be taking:

• Employee pension contributions from JOB.DEDUC1 * 52 (UDEDUC1 is mostly null)
• Personal pension contributions from PENPROV.PENAMT where STEMPPEN == 5 (this is pretty much all records with values)

Just confirmed that the latest FRS seems in line with both personal and employee totals below:

Employer pensions aren't in the FRS or the SPI, so we're going to have to impute them. I'd suggest that we follow, as a first approach for now, the percentage match from the data above: employer contributions are 160% of employee contributions.

[vahid-ahmadi]

"However, by law, you and your staff have to pay a minimum amount into your scheme. This is set at 8% of your member of staff's earnings. You, the employer, must pay at least 3% of this, but you can choose to pay more."

It says almost the same. For the estimation, 160% of employee contributions are ok.