19 was a number.
The Rani's time brain thought that 87K to the power of 19E correlated with 52 to the power of 6.4 equals 29V. The Seventh Doctor corrected it to 39. (TV: Time and the Rani [+]Loading...["Time and the Rani (TV story)"])
Rose Tyler was nineteen years old when she met and began travelling with the Ninth Doctor. (TV: Rose [+]Loading...["Rose (TV story)"], Dalek [+]Loading...["Dalek (TV story)"], PROSE: Rose Tyler [+]Loading...["Rose Tyler (short story)"], The Doctor Was Involved in the Dummy Massacre [+]Loading...["The Doctor Was Involved in the Dummy Massacre (short story)"]) However, other accounts indicated she was around seventeen. (TV: Father's Day [+]Loading...["Father's Day (TV story)"], Rise of the Cybermen [+]Loading...["Rise of the Cybermen (TV story)"], PROSE: Meet Rose [+]Loading...["Meet Rose (short story)"])
Ruby Sunday met and began travelling with the Fifteenth Doctor on her nineteenth birthday. (TV: The Church on Ruby Road [+]Loading...["The Church on Ruby Road (TV story)"])
Chronon, (WC: 14682 UNIT Field Log [+]Loading...["14682 UNIT Field Log (webcast)"], 14683 UNIT Field Log [+]Loading...["14683 UNIT Field Log (webcast)"], 14684 UNIT Field Log [+]Loading...["14684 UNIT Field Log (webcast)"]) or cronon (WC: 14681 UNIT Field Log [+]Loading...["14681 UNIT Field Log (webcast)"]) and artron energy readings during the recording of UNIT field logs included 17%, (WC: 14682 UNIT Field Log [+]Loading...["14682 UNIT Field Log (webcast)"]) 18%, 19%, (WC: 14681 UNIT Field Log [+]Loading...["14681 UNIT Field Log (webcast)"], 14682 UNIT Field Log [+]Loading...["14682 UNIT Field Log (webcast)"]) 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, (WC: 14682 UNIT Field Log [+]Loading...["14682 UNIT Field Log (webcast)"]) 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, (WC: 14682 UNIT Field Log [+]Loading...["14682 UNIT Field Log (webcast)"], 14684 UNIT Field Log [+]Loading...["14684 UNIT Field Log (webcast)"]) 90%, (WC: 14682 UNIT Field Log [+]Loading...["14682 UNIT Field Log (webcast)"], 14683 UNIT Field Log [+]Loading...["14683 UNIT Field Log (webcast)"]) 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, 101%, 102%, 103%, 104%, 105%, 106%, and, in the case of Chronon energy, 107%. (WC: 14683 UNIT Field Log [+]Loading...["14683 UNIT Field Log (webcast)"])