Above should read 1,000 blocks in both instances (not 10,000). Technically it's 1,008, based on the maximum horizon value. This is chosen arbitrarily to target 1 week of blocks.
/// Bucket depth sizing parameters (number of blocks).
enum horizon : size_t
{
/// 2 hrs × 60 mins/hr / 10 mins/block = 12 blocks.
small = 12,
/// 8 hrs × 60 mins/hr / 10 mins/block = 48 blocks.
medium = 48,
/// 7 days * 24 hrs/day × 60 mins/hr / 10 mins/block = 1008 blocks.
large = 1008
};