new UnitConverter:

total time: 21.008330821991
failed conversions: 264
per conversion:
  mean time: 0.0115430389131818
  standard deviation: 0.139564324874432
  median time: 0.00139093399047852

old UnitConverter:

total time: 210.900288105011
per conversion:
  mean time: 0.115879279178577
  standard deviation: 0.984125152107407
  median time: 0.00746679306030273