FSC = Full Service / Legacy / Network carriers.
Top-5 market share at each:
LHR
BA (48.9%)
VS (4.5%)
UA (3.7%)
LH (2.8%)
EI (2.7%)
LGW
U2 (37.9%)
BA (14.6%)
DY (6.7%)
MT (5.5%)
ZB (5.3%)
STN
FR (80.1%)
U2 (11.4%)
MT (2.2%)
BY (1.8%)
PC (1.4%)
LTN
U2 (39.6%)
W6 (30.3%)
FR (12.3%)
ZB (5.9%)
BY (3.4%)