These are customers they already know I presume. So they have an inkling of the expected mileage (at least: we price on expected mileage). So you repeatedly sam

These are customers they already know I presume. So they have an inkling of the expected mileage (at least: we price on expected mileage). So you repeatedly sample dropping some samples to get enough filling in all mileage baskets. It’s a stratified sample and random. Say you have 10k customers with 1k women. You want to take a sample And want enough power to get answers on women. In that case you do stratified sampling.