calculate person impact percentiles when impact is null
calculate person impact percentiles when impact is null

total-impact/software,total-impact/depsy,total-impact/software,total-impact/depsy,total-impact/software,total-impact/depsy,Impactstory/depsy,Impactstory/depsy,Impactstory/depsy,total-impact/depsy,total-impact/software,Impactstory/depsy