Update R12_NAM mode share

Update R12_NAM mode share to avoid covid dip from iea-eweb 2020 values, rather align with 2019 values

Author: r-aneeque

message_ix_models/data/transport/R12/mode-share/default.csv

@@ -44,9 +44,9 @@ R12_MEA,  BUS,        0.38
 R12_MEA,  LDV,        0.43
 R12_MEA,  RAIL,       0.01
 R12_NAM,  2W,         0.005
-R12_NAM,  AIR,        0.11
+R12_NAM,  AIR,        0.12
 R12_NAM,  BUS,        0.06
-R12_NAM,  LDV,        0.81
+R12_NAM,  LDV,        0.805
 R12_NAM,  RAIL,       0.01
 R12_PAO,  2W,         0.01
 R12_PAO,  AIR,        0.13