Using a definition of 'repair' as being about anything that requires the use of some kind of tool ...
In order of how often I have encountered them (roughly)
1) Flat tires partially mitigated by riding tougher tires (less comfort/other negatives), care with tire pressures, care in choosing where you ride
2) Tire replacement - some tires wear faster than others (typically a life, speed, comfort, handling trade-off)
3) Chain replacement partially mitigated by regular cleaning and lubing
4) Adjustment of shifters and brakes - seems inevitable to me
5) Broken spokes - not frequent and I am not sure how or why they happened
6) worn rear cassettes partially mitigated by proper chain replacement. Worn chains get longer and dramatically affect the life of a cassette
7) Wheel truing
dave