length distribution, all arms, raw generations (the 90-140 band is what the register asks)
arm          n  median   p10   p90   max  in-band  under90  over140  TOTAL out
base       240     110    89   126   149     0.89      10%       1%        11%
ckpt225    240     127    89   206   296     0.52      10%      38%        48%
ckpt300    240     101    83   151   216     0.65      22%      13%        35%
ckpt450    240     107    87   171   297     0.67      14%      20%        33%
ckpt900    240     114    92   190   279     0.67       5%      28%        33%