20Btu (mean) |
20.02Btu (I.T., pre-1956) |

21Btu (mean) |
21.02Btu (I.T., pre-1956) |

22Btu (mean) |
22.02Btu (I.T., pre-1956) |

23Btu (mean) |
23.02Btu (I.T., pre-1956) |

24Btu (mean) |
24.02Btu (I.T., pre-1956) |

25Btu (mean) |
25.02Btu (I.T., pre-1956) |

26Btu (mean) |
26.02Btu (I.T., pre-1956) |

27Btu (mean) |
27.02Btu (I.T., pre-1956) |

28Btu (mean) |
28.02Btu (I.T., pre-1956) |

29Btu (mean) |
29.02Btu (I.T., pre-1956) |

30Btu (mean) |
30.02Btu (I.T., pre-1956) |

31Btu (mean) |
31.02Btu (I.T., pre-1956) |

32Btu (mean) |
32.03Btu (I.T., pre-1956) |

33Btu (mean) |
33.03Btu (I.T., pre-1956) |

34Btu (mean) |
34.03Btu (I.T., pre-1956) |

35Btu (mean) |
35.03Btu (I.T., pre-1956) |

36Btu (mean) |
36.03Btu (I.T., pre-1956) |

37Btu (mean) |
37.03Btu (I.T., pre-1956) |

38Btu (mean) |
38.03Btu (I.T., pre-1956) |

39Btu (mean) |
39.03Btu (I.T., pre-1956) |