Ca, Co and Cu aren't even in the fifth period. The trend is increasing mass from left to right. If you look at Sb-Te-I, you will see that Te has a greater atomic mass than Sb or I. You could even say that iodine doesn't fit the pattern of increasing atomic mass, rather than tellurium. Then again, it really doesn't matter, because the periodic table is not arranged by atomic mass, as it was in the distant past. Instead the period table is arranged by increasing atomic number.
Only the last two of those are even in the fifth row, however all of them have an increased atomic mass compared to the element immediately to the left of them.
Iodine is the only element in the fifth row that has a lower atomic mass then the element to the left.
The atomic mass of Tellurium is 127.60.
The atomic mass of Iodine is 126.904472.