unsuccessful means that you search a cell in your hash table to put an element in it but it was already filled.
so you now apply open addressing or chaining to resolve your problem
in this case last element is 72 so it should be placed inside 2nd row.
so Probe 1: unsuccessful 62 was there :(
now you apply linear probing
probe 2 : unsuccessful 83 was there :(
probe 3 : unsuccessful 84 was there :(
probe 4 : unsuccessful 95 was there :(
probe 5 : unsuccessful 74 was there :(
probe 6 : unsuccessful 23 was there :(
probe 7 : unsuccessful 86 was there :(
probe 8 : successful it was empty so we can put 72 there :)
so 7 unsuccessful probe