Diff oht = -0.064700 (Y 852)      // PUBLISHED
   Diff oht = -0.089000 (GLEN)
   Diff oht = -0.117500 (C 200)       // PUBLISHED
   Diff oht = -0.142000 (Y 850)       // PUBLISHED
   Diff oht = -0.195100 (P 1430)      // PUBLISHED
   Diff oht = -0.215800 (Q 1078)      // PUBLISHED
   Diff oht = -0.219800 (K 852)        // PUBLISHED
   Diff oht = -0.254200 (U 1078)     // PUBLISHED
   Diff oht = -0.255100 (HAMI)
   Diff oht = -0.258900 (H 285 USGS)   // PUBLISHED
   Diff oht = -0.277000 (N 852)        // PUBLISHED
   Diff oht = -0.295200 (A 1079)        // PUBLISED
   Diff oht = -0.311400 (V 380 RESET 1967)  // PUBLISHED
   Diff oht = -0.338100 (Y 380)    // PUBLISHED
   Diff oht = -0.362300 (ORLAND SOUTH BASE)   // PUBLISHED
   Diff oht = -0.368300 (WINSLOW)     // PUBLISHED
   Diff oht = -0.371600 (B 1079)       // PUBLISHED
   Diff oht = -0.394900 (S 1067)       // PUBLISHED
   Diff oht = -0.436300 (W 215 AZ MK)  // PUBLISHED
   Diff oht = -90.568400 (CREE)
   Diff oht =  0.044500 (J 1434)          // PUBLISHED
   Diff oht =  5.478900 (NORM)
   Diff oht = 16.882200 (1118)
   Diff oht = 25.778200 (1122)