Singapore Speed ratings and exotics

Speed ratings for main contenders –

PA : 1+4 x 3+4 x 8+12 x 1+3 x 1+4 x 3+10 x 3+7 = 64 perms

Jackpot : 1,3,6 x 1,4,9 x 2,3,10 x 1,3.7 = 81 perms

Race 6
93…Fighting Warrior
92…River of Gold
89…Lady Roulette
88…Super Joy
88…Stock Brocker
87…Meaisin

Race 7
116…Olympic Anthem
112…Good News
111…Pioneer Seven
110…Sebas
109…Indian Jade

Race 8
98…Lim’s Action
93…Mr.Connery
93…Thunder Cat
91…Jubilation
91…Lee Man
90…Rock of Ages

Race 9
109…Hermano Menor
108…Squire Osbaldeston
104…Brahma Circus
102…WonderfulPrince
102…Mr.Spielberg
101…Above the Skyline

What is a speed rating exactly?