Here, All male divisions for the past 4 years. Take your own conclusions!
Note: I don't count Interim because it is not the real title. If/when they unify, I did count.
HW Belt
Stipe & DC
0 fights in 2020
1 fight in 2019 (Stipe & DC)
2 fight in 2018 (Stipe & DC)
1 fight in 2017 (Junior)
4 fights in 4 years
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LHW Belt
Jon Jones
1 fight 2020 (Reyes)
2 fights 2019 (Smith, Santos)
1 fight 2018 (DC)
DC
1 fight 2017
5 fights in 4 years
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MW belt:
Israel Adesanya -
1 fight 2020 (Yoel)
Robert Whittaker -
1 fight 2019 (Adesanya)
1 fight 2018 (Yoel)
1 fight 2017 (Yoel)
4 fights in 4 years
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WW Belt
Usman
0 fights in 2020
2 fights in 2019 (Colby, Woodlwy)
1 fight 2018 (Til)
2 fights in 2017 (Maia, Thompson)
5 fights in 4 years
===================================
LW Belt
Khabib
0 fights in 2020
1 fight in 2019 (Dustin)
2 fights in 2018 (Conor, Iaquinta)
0 fights in 2017
3 fights in 4 years
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FW Belt
Volkanovski
0 fights in 2020
Max:
2 fight in 2019 (Volkanovski, Frankie)
1 fight in 2018 (Ortega)
2 fights in 2017 (Aldo*2)
5 fights in 4 years
===================================
BW Belt
1 fight in 2020 (cruz)
0 fights in 2019 (Cejudo Marlon)
1 fight in 2018 (Cody)
1 fight in 2017 (Cody)
3 fights in 4 years
===================================
FLW Belt
0 fight in 2020
1 fights in 2019 (TJ)
1 fight in 2018 (DJ & Cejudo)
2 fight in 2017 (Borg, Reis)
4 fights in 4 years
Total
3 belts defended 5 times in 4 years
3 belts defended 4 fights in 4 years
2 belts defended 3 fights in 4 years
So the best, most active divisions fought 5 times in 4 years....
Please tell me again how active they are!!!!