In many parts of the world, there has not been private radio broadcasting until the past few decades. In many nations, the dial was dominated by national public or state-run broadcasters such as the BBC in the UK, RTÉ in Ireland, ABC in Australia and RNZ in New Zealand.
On a worldwide basis, there was no true FM broadcast allocation. There still isn't with Japan having their broadcast band between 76~95 MHz. Eventually as countries introduced VHF FM radio broadcasting, the entire spectrum may have not been available. In the UK up until the early 90s., only the lower part of the FM band (approximately below 98 MHz) was available for FM broadcasting. The upper part of the band was allocated to land mobile services. During that time, tuning across the high end of an FM radio, one could hear police and taxicab communications.
New Zealand was in the same situation. VHF FM was not introduced to the country until the mid-1970s. Years earlier, New Zealand was considering allocating spectrum around the FM broadcast band to the archiac 405-line Marconi System-A monochrome system that the UK used from the 1930s until the mid-80s. Apparently those spectrum set-asides remained until the mid-70s when the NZ government allocated the 88~105 MHz band (which was likely the spectrum originally reserved for System A television) to VHF sound broadcasting. NZ decided to go with the PAL color system that operated outside of the 88~105 spectrum. There was no broadcasting allocation from 105~108 MHz. It's possible that the 105~108 MHz spectrum may have served as a guard band for the worldwide aeronautical radionavigation allocation starting at 108 MHz.
FM radio in New Zealand did not begin until 1982 and even then, the number of broadcast stations were very limited due to the proliferation of public broadcasting and the limited number of private radio licenses at the time. Again, this was true for many nations of the world.
It was not until the late 90s when New Zealand allocated 105~108 to FM sound broadcasting and around 2010, was extended downwards towards 87.5, which was commonplace for many ITU Region 1 and 3 administraitons to operate at, especially with the shutdown of analog television in the VHF low band spectrum.
In New Zealand, the General User Radio License (GURL) is a comprehensive regulatory scheme that covers all kinds of radio services including some that require individual licensing like Amateur Radio and those that do not like CB radios, cordless phones and low power FM (LPFM) broadcasting.
The LPFM GURL allows for operation of up to 1 watt EIRP on spot frequencies from 87.6~88.3 and 106.7~107.7 (100 kHz increments). The 106.7~107.7 spectrum is not available in areas near the Auckland and North Wellington Airports in order to protect the aeronatuical services. There is a restriction on simulcasting on stations wtihin 25 km of each other and other broadcast content rules that apply to full-power NZ broadcast stations also apply to the GURL LPFM stations.
Based on this, New Zealand was able to allocate this spectrum for license-free LPFM operations because their spectrum was not as substantially crowded as it is here in the USA. In the USA, the spectrum from 88~106 MHz was originally allocated to sound broadcasting while the spectrum 106~108 MHz was allocated to facsimilie broadcasting (imagine having a device like a fax machine in your house and it would print out a copy of the front page of the paper). The concept of facsimilie broadcasting would eventually be abandoned and this spectrum would be allocated to FM to form the 100 channels we have today.
The original Leggett/Skinner LPFM proposal in RM-9208 called for a dedicated LPFM frequency in both the AM and FM bands. This concept was later amended to exclude the dedicated-channel concept. The idea of a dedicated channel would never work here in the USA because of how channels are allocated. In addition, even if one of the 100 channels could be dedicated to LPFM services, it would not be available nationwide because of first-adjacent channel protection requirements. One channel would really require at least two channels (one channel to serve as a guard band). REC had proposed in the past to use 87.5 and 87.7 for additional channels for a licensed LPFM service (in addition to the rest of the band). Even if 87.5 and 87.7 were made available for a 1-watt ERP low power FM license-free application, its availability would be limited due to incumbent Channel 6 full-power and low-power TV operations.
The only way that we could ever have any kind of a license free band like New Zealand would be if we were to reallocate TV channels 5 and 6 (76~88 MHz) and dedicate some spectrum (perhaps a guard band from 76.1~76.9) for license free broadcasting. With the renewed interest in low band VHF spectrum due to the evolution of next-gen digital television and the FCC willing to allocate "companion channels" to TV licensees to deploy next-gen, a sound allocation in this spectrum is now less likely. Other spectrum that could be considered is the extended AM broadcast band which is under-utilized and it could be a natural upgrade of the existing Part 15 AM rules to allow higher-powered (perhaps 500 milliwatts instead of 100) in the 1620~1700 kHz spectrum. This could still be done even if new stations are licensed in this spectrum under FCC Chairman Ajit Pai's AM Revitalization initative.
39 FCC 230 (Includes information on the early creation of the FM band between 88~106 and then extended to 108)